Guides/Comparisons
Ferrous and non-ferrous metals
ferrous-and-non-ferrous-metalsFerrous metals and Non-ferrous metals at a glance
This page compares Ferrous metals and Non-ferrous metals using only values that carry a source, a test condition and an evidence level. Ranges run across temper, heat treatment and product form, measured at room temperature where the source says so.
Ferrous metals are iron-based: steels, stainless steels, tool steels and cast irons. Non-ferrous metals are not: aluminium, titanium, copper, nickel, zinc, magnesium and the refractory metals. Each side below uses every grade in this database that meets the full-grade bar, so the ranges are wide. Open a family or a grade for the values by temper and condition.
- Yield strength: the ranges overlap (Ferrous metals 165 to 1,896 MPa; Non-ferrous metals 29 to 1,434 MPa).
- Tensile strength: the ranges overlap (Ferrous metals 138 to 2,200 MPa; Non-ferrous metals 60 to 2,900 MPa).
- Density: the ranges overlap (Ferrous metals 7.2 to 8.1 g/cm³; Non-ferrous metals 1.74 to 21 g/cm³).
- Young's modulus: the ranges overlap (Ferrous metals 103 to 220 GPa; Non-ferrous metals 45 to 460 GPa).
- Thermal conductivity: the ranges overlap (Ferrous metals 12 to 93 W/(m·K); Non-ferrous metals 0.71 to 430 W/(m·K)).
- Melting point: the ranges overlap (Ferrous metals 1,300 to 1,532 °C; Non-ferrous metals 232 to 3,422 °C).
- Service temperature: the ranges overlap (Ferrous metals 232 to 1,100 °C; Non-ferrous metals 65 to 2,200 °C).
- Thermal expansion: the ranges overlap (Ferrous metals 3.44 to 20.5 ppm/K; Non-ferrous metals 4.5 to 27.3 ppm/K).
- Yield strength for each unit of density (calculated from each grade's midpoint values): Ferrous metals 23.8 to 248 MPa per g/cm³; Non-ferrous metals 7.73 to 229 MPa per g/cm³.
"Higher" means the whole range is higher, not just one value. Where a value is a specified minimum, the table says "at least".
Side by side
| Property | Ferrous metals | Non-ferrous metals |
|---|---|---|
| Yield strength | 165 to 1,896 MPa | 29 to 1,434 MPa |
| Tensile strength | 138 to 2,200 MPa | 60 to 2,900 MPa |
| Density | 7.2 to 8.1 g/cm³ | 1.74 to 21 g/cm³ |
| Young's modulus | 103 to 220 GPa | 45 to 460 GPa |
| Thermal conductivity | 12 to 93 W/(m·K) | 0.71 to 430 W/(m·K) |
| Melting point | 1,300 to 1,532 °C | 232 to 3,422 °C |
| Service temperature | 232 to 1,100 °C | 65 to 2,200 °C |
| Thermal expansion | 3.44 to 20.5 ppm/K | 4.5 to 27.3 ppm/K |
| Yield strength per densitycalculated | 23.8 to 248 MPa per g/cm³ | 7.73 to 229 MPa per g/cm³ |
When to use which
| Material | Best for | Weakest at |
|---|---|---|
| A36 structural carbon steel | Welded and bolted structural frames, girders and shapes that will be painted or galvanized | Rusts outdoors and corrodes first when it touches copper or tin in a wet electrolyte; minimum strength falls above 650 °F (343 °C) |
| Carbon steel 1018 | Machined shafts, pins and gears, and cost-sensitive structural parts that are coated against rust | Rust in moist air and salt unless it is coated, and strength that depends on whether the bar was cold drawn or hot rolled |
| Carbon steel 1045 | Forged or machined axles, shafts, gears and machine parts that need more strength than low-carbon steel, and that are coated against rust | Rust in moist air and salt unless it is coated, and strength that depends on whether the bar was cold drawn, hot rolled, normalised or annealed |
| Carbon steel 1215 | Screw-machine parts such as bushings, inserts, pins, studs and couplings, where machining speed and surface finish matter more than weldability (Alro; Titanium Industries) | Welding and fatigue. Alro says it is difficult to weld, and Titanium Industries says it fails in parts under severe fatigue stress |
| Alloy steel AISI 4130 | Aircraft and motorsport tube, sheet and bar, and oil and gas parts, where weldability and strength after heat treatment both matter | Hydrogen gas and salt solutions: in one laboratory study the threshold stress intensity fell from 88 to 32 MPa√m as hydrogen pressure rose from 21 to 69 MPa, and salt solution cut corrosion-fatigue life |
| Alloy steel AISI 4140 | Machine parts and structures in medium and large sections that need high strength and toughness after quenching and tempering | Hydrogen gas, which cut notched strength by about 60 percent in one room-temperature study, and dilute sulfuric acid, which corroded it at 176.87 mpy |
| Carbon steel 1010 | Formed, drawn and welded parts, and light structural parts, where cost and ductility matter | Rust in moist air and salt unless it is coated, and strength that depends on the processing condition |
| Carbon steel 1070 | Springs, shafts and hand tools that are heat treated and kept dry or coated (tensile strength 640 to 700 MPa in the supplier range) | Corrosion, which is poor without a coating, brittleness once fully hardened, and poor weldability |
| Alloy steel AISI 4340 | Large sections that need high tensile strength and toughness after quenching and tempering, such as aircraft landing gear, gears and shafts (voestalpine, Saky Steel). | Toughness at the highest strength levels: the minimum Charpy impact energy falls from 42 J at condition U to 9 J at condition Z (voestalpine). No corrosion data were read for this grade. |
| Stainless steel 304 | Corrosion-resistant housings, fasteners and tanks where ordinary steel would rust | Chloride pitting in acidic solutions, and low strength compared with precipitation-hardened steels |
| Stainless steel 316 | Chloride-bearing and marine-grade service where 304 would pit, in annealed sheet, bar and plate | Crevice and pitting attack in seawater condenser tubes, intergranular attack after heating between 500 and 900 C, and modest strength next to precipitation-hardened grades |
| Stainless steel 316L | Welded parts in chloride or marine service, and vacuum hardware that is vacuum-fired | Long holds near 650 C form sigma phase, and seawater service needs a pitting resistance equivalent number greater than 40 (Wikipedia) |
| Duplex stainless steel 2205 | Chloride-bearing and sour service where 300-series steels crack, in welded pipe, tube, sheet and plate (ATI, Alleima) | Extended exposure at 343 to 530 C (475 C embrittlement), welds made with straight chromium filler, and sour service above 232 C (ATI, Alleima) |
| Super duplex stainless steel 2507 | Chloride-bearing seawater, subsea and sour oil and gas service that needs high strength and pitting resistance, in solution-annealed tube, bar and forgings | Prolonged exposure above 250 °C, which lowers impact strength, and hydrogen-induced cracking in cathodically protected subsea steel |
| 17-4 PH stainless steel | High-strength fittings, fasteners, shafts and valve parts that need more strength than 304 and moderate corrosion resistance | Stress corrosion cracking and pitting in peak-aged (H900) material, and crevice corrosion in stagnant salt water |
| Stainless steel 440C | Bearings and valve parts that must be hard and wear-resistant in the hardened and tempered condition (Carpenter, Aalco, Rolled Alloys) | Corrosion resistance in the annealed state or after tempering above about 800 F (427 C), and service above about 400 C (NASA 2018 maximum use temperature) |
| Stainless steel 410 | Hardened and tempered valve, shaft and fastener parts that need strength and a magnetic response | Chloride, marine and strong-acid service, and toughness after tempering at 482 to 538 C |
| Stainless steel 430 | Sinks, appliance trim and architectural cladding, where economy and moderate corrosion resistance matter more than strength (ATI) | Welds and sea water. Welds lose ductility and corrosion resistance, and the datasheet says the grade is not resistant to sea water (Deutsche Edelstahlwerke) |
| Martensitic stainless steel 13Cr-4Ni (UNS S41500) | Quenched and tempered turbine, pump and valve parts that need good strength and low-temperature toughness, in low-chloride media with polished surfaces | Chloride pitting (DEW: slight attack with a risk of pitting in saturated NaCl at 20 C), the 23 HRC cap for sour gas, and poor weldability (DEW) |
| Stainless steel 301 | Springs, clips and light formed structures where cold-work strength matters more than corrosion resistance | Chloride pitting (critical pitting temperature below 10 C in Outokumpu's test) and carbide precipitation after welding or holding at 427 to 816 C |
| Stainless steel 303 | Heavily machined parts in mild service, such as screws, nuts, bolts, shafts and fittings (Aalco, UPMET) | Chloride and marine service, where Aalco says 303 is not suitable, and welded joints, where Aalco says weldability is poor |
| Lean duplex stainless steel 2304 | Chloride-bearing process piping and heat exchangers, pulp and paper equipment, and strength-limited structures where 304 or 316 would crack or be too weak (Alleima, ATI) | Exposure above about 315 C (600 F), where 475 C embrittlement can follow (ATI); prolonged exposure above 280 C (Alleima); weld metal without an overmatched filler (ATI) |
| Stainless steel 409 | Automotive exhaust systems and heat exchangers, where corrosion protection is needed beyond carbon steel (Combined Metals) | Pitting and intergranular corrosion: Outokumpu prints a critical pitting temperature below 10 °C and N/N for intergranular corrosion, and Aalco limits welded sheet to about 2.5 mm thick |
| Stainless steel 444 | Hot water tanks, heat exchangers and solar tanks in chloride-bearing water, where resistance to chloride stress cracking matters (ATI, Ugitech, Aperam) | Boiling 10 percent sulphuric and sulfamic acids, where ATI's table shows corrosion above 1000 mils per year, and toughness at transition temperatures, welds included (Aperam) |
| AISI 302 stainless steel | Springs, washers, screens and wire parts that need an 18-8 stainless steel with more carbon than 304 for strength, while keeping ductility (Elgiloy datasheet) | Strength in the annealed state (about 290 MPa typical yield), and ductility after heavy cold work (elongation falls from 48 % at 0 % cold work to 2.2 % at 80 % cold work, fwmetals table) |
| Stainless steel 304L | Welded parts in corrosive service, where the as-welded condition must resist carbide precipitation | Sea water and chloride service: Carpenter rates 304 and 304L restricted in sea water, and no pitting number for 304L was found |
| Stainless steel 310S | Furnace and heat-treatment parts that run hot in oxidising air up to about 1,050 °C, with good creep strength and oxidation resistance | Sulphur-bearing hot gases, which cut the service limit to 950 °C, and long exposure between 650 and 900 °C, which causes sigma-phase embrittlement and chromium-carbide sensitisation |
| AISI 317L stainless steel | Chloride pitting resistance in process equipment, with a low-carbon grade that limits sensitization in welds | Strength in the annealed state (205 MPa minimum yield) and chloride stress cracking above about 49 °C |
| AISI 321 stainless steel | Welded parts that run hot in oxidising air, from 427 to 850 degC: titanium holds the grade against carbide precipitation in the 800 to 1500 degF range | Strength when annealed (about 241 MPa typical yield) and cold-work strength only, plus exposure of 900 to 1500 degF for long periods, which lowers general corrosion resistance |
| AISI 347 stainless steel | Welded hot-service parts that cannot be re-annealed afterwards: niobium stabilisation resists intergranular attack, and the grade is rated to 800 °C in air | Strength when hot: tensile strength falls from 93.3 ksi at 68 °F to 69.5 ksi at 800 °F (Rolled Alloys), and no vacuum, radiation or atomic-oxygen data were found |
| AISI 347H stainless steel | Welded parts for hot service in air and steam, where creep strength to 1500 degF is needed and niobium stabilisation resists intergranular attack in the as-welded condition | Strength when hot: typical tensile strength falls from 93.3 ksi at 68 degF to 69.5 ksi at 800 degF (Rolled Alloys), and no vacuum, radiation or atomic-oxygen data were found |
| Super-austenitic stainless steel 904L | Sulfuric and phosphoric acid plant, seawater condensers and heat exchangers, and pulp bleaching, in annealed sheet, plate, strip and tube, where 316L or 317L would corrode | Halide-containing acids and boiling magnesium or lithium chloride, where ATI's U-bend test cracked the alloy, and crevices in chloride water (ATI G-48 onset at 18 °C) |
| Nitronic 60 stainless steel | Fasteners, pins, bushings and valve trim that must resist galling and wear while staying austenitic and low in magnetic permeability | General corrosion resistance falls between Types 304 and 316, the alloy is hard to machine, the high-strength bar cannot be hot worked or welded without losing strength, and the sources print no space-environment data |
| Lean duplex stainless steel 2101 (UNS S32101) | Chloride-bearing process equipment where a 300 series grade is too weak or too prone to chloride stress cracking, and nickel cost matters: the grade gives about double the 0.2 % yield of 304 and 316 and no SCC in the boiling CaCl2 U-bend test | Use above about 300 °C: Atlas says held above 300 °C the grade embrittles and only a full solution anneal restores it, and no space-environment data (radiation, outgassing, cryogenic toughness) were found |
| Stainless steel 430F | Machined parts cut from bar on automatic screw machines, where machinability matters more than corrosion resistance or weldability (Atlas, Deutsche Edelstahlwerke) | Corrosion and welding. The sulphur addition reduces corrosion resistance, especially pitting and crevice attack, and weldability is poor (Deutsche Edelstahlwerke) |
| Stainless steel 410S | Ferromagnetic, weldable stainless parts for hot or mildly corrosive service, such as distillation trays, tower packing and exhaust components, where the 410 hardening response is not wanted | Chloride and marine service (no 410S test data was found), and room-temperature brittleness in thick sections (Jacquet) |
| AISI 416 stainless steel | Shafts, axles, gears, valve and pump parts and screw-machine parts that must be cut quickly and then hardened, kept away from chloride exposure | Corrosion resistance. The sulfur addition lowers it below the non-free-machining grade 410, and the Aalco datasheet calls high-sulfur free-machining grades totally unsuitable for marine or chloride exposure |
| Stainless steel 420 | Hardened wear parts, blades and bearing-type components that need high strength and edge retention, from one steel that reaches 48 HRC after tempering at 440 °F | Corrosion resistance and ductility: it resists corrosion less well than austenitic grades, and it loses strength when tempered at 1000 °F (158.5 ksi tensile) |
| Stainless steel 431 | High tensile and torsional strength in shafts, valve stems and pump parts that also need reasonable corrosion resistance (Smith Metal, Smiths High Performance) | Welding and cold forming: welds crack unless preheated, and the grade is not recommended for cold heading or bending (Smiths High Performance, Voestalpine) |
| Martensitic stainless steel | Quenched and tempered shafts, axles and pump parts that need strength, toughness and good general corrosion resistance, with limited marine exposure (DEW) | Chloride pitting: DEW gives a risk of pitting corrosion in saturated sodium chloride and in sea water at 20 C, and welds need heat treatment afterwards (DEW) |
| 17-7 PH stainless steel | Springs, Belleville washers, eyelets and flat springs that need high strength and stainless corrosion resistance, with formability in the soft state | Stress corrosion cracking in chloride and in nitrogen tetroxide/hydrazine propellant, in every heat-treated condition except CH 900; ductility in CH 900 (2 % elongation) |
| PH 15-7 Mo stainless steel (15-7 PH) | Springs, retaining rings and seal rings that need high strength with a low-distortion hardening heat treatment (ATI and Ulbrich list these uses) | Stress corrosion cracking in salt water: the 1969 NASA test found the alloy cracked in all conditions except CH 900, and corrosion resistance is below Type 304 (ATI) |
| AISI D2 cold-work tool steel | Blanking, punching, forming and cutting tools that need high wear resistance more than toughness | Toughness and corrosion: rather limited cracking resistance (Uddeholm), and corrosion resistance below that of stainless steel (Wikipedia) |
| P20 plastic mould steel | Plastic injection-mould blocks, mould frames and bolsters that are machined in the pre-hardened condition and then polished (Smith Metal Centres; Oberste-Beulmann; Abrams). | Corrosion resistance. The datasheets say it is not corrosion resistant and rusts unless protected; Aços Formosa points PVC and gas-releasing plastics to the stainless grade 1.2316 instead. |
| 1.2316 stainless plastic mould steel | Moulds and tools for PVC and other corrosive plastics that need a stainless, polishable face in the quenched and tempered condition (Aços Formosa; Dörrenberg; Abrams). | Corrosion data are qualitative: no test is printed, and the stated range is atmospheric, humid, weak acid and alkali service (Abrams). Machinability is rated only 2 on a 1 to 6 scale (Abrams). |
| 1.2738 plastic mould steel | Large plastic injection-mould blocks, cores and frames that are machined in the supplied condition and then polished, and hydroforming tools and dies (Dörrenberg; Industeel; Oberste-Beulmann; Abrams). | Corrosion resistance. Abrams says the grade has a certain degree of corrosion resistance but is not stainless: 1.8 to 2.1 percent chromium is far below the 10.5 percent it gives as the minimum for stainless steel. Reheating or tempering at 600 °C or above lowers hardness. |
| AISI H13 hot-work tool steel | Die-casting, extrusion and forging tools that run hot and need hardness, strength at elevated temperature and resistance to heat checking | Corrosion: no corrosion rating or test for H13 was found in the fetched sources. Uddeholm also warns that tempering between 425 and 550 °C causes temper brittleness. |
| Gray cast iron | Machine bases, frames, pump housings and engine blocks, where damping, machinability and compressive load matter more than tensile strength | Tensile strength and shock resistance: the graphite flakes act as notches, so the metal breaks in a brittle way |
| Ductile iron | Castings that need the ASTM A536 strengths of 60,000 to 120,000 psi, such as high-strength gears and rollers and pressure-containing valve and pump bodies (Goldens; Daycounter) | Elongation falls as the grade rises, from 18 percent at 60-40-18 to 2 percent at 120-90-02 (Goldens). Properties also depend on the heat treatment that each grade requires (ASTM A536 summary) |
| Aluminium alloy 6061 | A light, workable structural metal with good corrosion resistance (the NASA handbook ranks 6061 best of the heat-treatable aluminium alloys for corrosion) | Galvanic attack when coupled to more noble metals, especially in sea water (NASA handbook); typical strength values are marked not for design |
| Aluminium alloy 7075-T6 | High-strength aluminium parts where low mass and wrought forms such as tube, plate, bar or forging are useful | Stress-corrosion cracking in the short-transverse direction in T6, and relatively poor corrosion resistance in industrial and marine environments |
| Aluminium alloy 2024 | A high-strength wrought aluminium alloy for aircraft fittings and structural parts (the datasheets list these uses; ASM typical T4 yield strength is 324 MPa) | Stress-corrosion cracking of the 2024-T351 temper in seacoast and salt-water conditions (NASA 1981), and pitting in salt water |
| Aluminium alloy 5052 | Welded sheet and tank or marine-style parts at medium strength, where the temper is named and checked (the datasheets rate its seawater resistance very good) | Strength depends on temper (yield 13 ksi annealed to 37 ksi in H38), and no measured seawater corrosion rate was found in the sources read |
| Aluminium-magnesium alloys (5XXX series) | Welded, corrosion-resistant sheet and plate at moderate strength (5083 is sold for ship building and pressure vessels) | Strength per alloy is modest next to heat-treated 6061, and 5083 is not recommended above 65 °C because of grain-boundary attack |
| Aluminium-lithium alloy 2195 | Welded cryogenic tanks where friction stir welding keeps most of the strength (NASA reports, 1998 to 2008) | Fusion welding, which hot-cracks and needs repairs, and corrosion resistance, which the supplier calls poor |
| Aluminium | Light, cheap electrical and thermal conduction, and a positive-electrode foil that stays passive in common lithium-ion electrolytes | Strength: annealed pure aluminium has a typical yield strength near 22 to 29 MPa, so it is not a structural metal on its own |
| Aluminium alloy 1050 | Formed sheet, chemical plant and heat-transfer parts that need very good corrosion resistance and easy forming more than strength (Smiths and Righton list these uses) | Low strength in the soft tempers (Smiths gives 100 to 135 N/mm2 typical tensile for 1050A H14, and 1200 O is 70 to 105 N/mm2); no measured corrosion test data were read |
| Aluminium alloy 2011 | Small, complex, high-precision machined parts made on automatic lathes, such as screws, bolts, gears, fasteners and fittings (suppliers rate machinability very good to excellent) | Weldability (rated poor to extremely poor by the sources) and corrosion resistance (rated low to moderate, and anodising or another surface treatment is advised) |
| Aluminium alloy 2014 | High-strength structural parts for aerospace and defence, where a 460 MPa minimum tensile strength in T651 plate is needed and the part is clad or painted against corrosion | Corrosion resistance (poor in water and salt, with pitting and galvanic attack in sea water), and welding, which is difficult and prone to cracking |
| Aluminium alloy 2017 | High-strength machined parts and rivets in aircraft-type structures, in the T4 temper (supplier rates machinability excellent, strength very good) | Weldability (only resistance welding is suitable, per the AircraftMaterials datasheet) and corrosion resistance (rated moderate by the supplier, with no test data found for this grade) |
| Aluminium alloy 2017A | Machined structural parts and solid rivets in the T4 temper (supplier rates machinability Excellent, yield strength 276 MPa) | Welding (resistance welding only, per the Smith and AircraftMaterials datasheets) and corrosion resistance (rated moderate by one supplier and good by another, with no test data for this grade) |
| Aluminium alloy 2219 | Launch-vehicle and cryogenic tankage where weldability and fracture toughness matter (Smith datasheet: readily weldable, good fracture toughness; Alloys International: launch vehicle and cryogenic tanks) | Ductility in thick plate, where 5-inch T87 plate showed below 1 % in the short-transverse direction (NASA 2021), and general corrosion resistance, which Wikipedia describes as lower than other aluminium alloys |
| Aluminium alloy 3003 | Sheet and formed parts that need moderate strength, good workability and weldability, and resistance to atmospheric corrosion, such as storage tanks, chemical equipment and heat exchangers, with the temper named | Strength depends on temper, from 14 to 19 ksi tensile in O to 27 ksi minimum in H18, and no seawater rating or measured corrosion rate for 3003 was found in the sources read |
| Aluminium alloy 5083 | Welded marine structures and pressure vessels kept at or below 65 °C, where seawater resistance and strength matter (supplier datasheets) | Service above 65 °C, where the suppliers advise against use. It is a non-heat-treatable alloy (Dinco sheet). No space-environment data were found. |
| Aluminium alloy 5251 (AlMg2) | Welded marine and sheet-metal structures where seawater corrosion resistance and weldability matter more than peak strength, at 2.69 g/cm3 | Strength compared with heat-treatable alloys: H22 minimum proof stress is 120 MPa, and a good weld reaches only about 160 MPa (Smith) |
| Aluminium alloy 5754 (AlMg3) | Welded structures and marine or chemical service where seawater corrosion resistance matters, at a density of about 2.67 g/cm3 | Strength against heat-treatable aluminium alloys, since strength comes from the temper, and the risk of sensitisation in magnesium-rich grades held warm for long periods (no temperature threshold for this grade was verified) |
| Aluminium alloy 6013 | Light structural aluminium for aerospace and general structural use: 2.71 g/cm3 density, and 350 MPa yield in the T651 temper (supplier page) | Dust and chips ignite readily during machining (Hydro SDS). No fatigue, fracture-toughness or T6 temper data was opened, and the sources disagree on thermal expansion |
| Aluminium alloy 6063 | Architectural extrusions such as window and door frames, rails and trim that need a smooth anodised finish (Alloys International; AZoM). | Strength: Alloys International says 6061 is the higher-strength choice for structural parts, and no space-environment, cryogenic or galvanic data were found for 6063. |
| Aluminium alloy 6082 | Structural parts that must be strong but light: T6 and T651 plate with minimum proof stress 255 MPa and density 2.70 g/cm3 | Strength in the weld zone, which the supplier says is lowered by welding, and pitting or intergranular attack in chloride solution (lab immersion test at 50 °C) |
| Aluminium alloy 7050 (AA7050) | Thick, high-strength aerospace structure in the over-aged T74 or T7451 conditions, where high yield strength and good exfoliation resistance are needed | Weld zones: friction-stir welds of 7050-T7451 showed less cracking resistance than 7075-T651 welds in constant extension rate tests (2003 study) |
| Aluminium alloy 8011 (AA8011) | Thin, light foil and fin stock: 2.71 g/cm3 density with 210 to 220 W/(m·K) thermal conductivity in H19 foil at 20 °C | Yield strength and corrosion data are missing from this profile, and no spacecraft use was found in any source read |
| Commercially pure titanium, Grade 2 (UNS R50400) | Seawater, brine and chloride service where corrosion resistance and formability matter more than strength (Alleima and Smiths datasheets) | Strength: 345 MPa minimum tensile, well below Ti-6Al-4V (see the Ti-6Al-4V profile). Crevice attack in hot seawater from about 80 °C (Pang and Blackwood 2016) |
| Ti-6Al-4V | Strength-to-weight structures that must stay strong up to about 400 degC, such as aerospace forgings and bars (the datasheet gives 4.43 g/cm3 density and 830 to 950 MPa yield) | Low thermal conductivity (6.7 W/(m K) at 20 degC), and lower ductility once it is solution-treated and aged (6 to 10 % elongation) |
| Titanium alloy Ti-6Al-4V ELI (Grade 23) | Cold-service hardware and medical implants where toughness and low interstitial content matter (Carpenter; UPMET; Titanium Industries). | Thermal conduction: 6.6 W/(m K) at 20 degC is low for a metal (UPMET). The sources read give no room-temperature fracture toughness for commercial bar. |
| Titanium Grade 9, Ti-3Al-2.5V (UNS R56320) | Seamless hydraulic and fluid tube, corrosion-resistant pipe and sporting frames, where more strength than commercially pure titanium is needed with more formability than Grade 5 (Smiths datasheets, Bibus) | Strength below Grade 5: 620 MPa minimum tensile when annealed, against 895 MPa for Grade 5 (ASTM B265). No thermal, cryogenic or space data for this grade were read in this run. |
| TiAl | Light rotating parts that run hot, such as low-pressure turbine blades in GE engines, where a density near 3.8 g/cm3 and a stiffness of 168 GPa matter more than ductility | Room-temperature ductility, since cast Ti-48-2-2 elongates only 1.70 % at 23 degC and impact can crack thin sections |
| Beta 3 | Parts that are cold formed in the solution-treated state and then aged to high strength, such as TIMETAL 15-3 strip (1000 MPa minimum tensile after 8 h at 538 degC) | Ductility after ageing (TIMETAL 15-3 strip falls to 5 to 7 % elongation), and the Beta 3 strength data are missing from the sources read |
| Commercially pure titanium with palladium, Grade 11 (UNS R52250) | Chloride and reducing-acid chemical plant equipment, and desalination or marine service, where crevice corrosion resistance matters more than strength (S+D Metals and Elgiloy datasheets) | Strength: 240 MPa minimum tensile, below the 345 MPa minimum of Grade 2 (ASTM B265). No Grade 11 crevice-corrosion test temperature was found in the sources read for this profile |
| Commercially pure titanium, Grade 3 (UNS R50550) | Formed and welded parts that need more strength than Grade 2 while keeping weldability and corrosion resistance in oxidising, neutral and mildly reducing media (Smiths) | Strength: 450 MPa minimum tensile, well below Ti-6Al-4V (see the Ti-6Al-4V profile). Oxygen limit of 0.35 %, the highest of CP grades 1 to 3 in ASTM B265 Table 2 |
| Commercially pure titanium, Grade 7 | Chemical processing and hot chloride or acid service where crevice corrosion is the main concern and Grade 2 is not enough (ATI corrosion data sheet; Elgiloy datasheet) | Strength: 345 MPa minimum tensile, the same as Grade 2 and well below Ti-6Al-4V. Its crevice limit depends on pH and temperature, and no Grade 7 test at pH 1 or below was read in this run |
| Minor titanium alloys, Ti-Mo, Ti-V, Ti-Fe, Ti-Si | Ti-10V-2Fe-3Al for forged, heat-treated structural parts that must hold about 1000 N/mm2 tensile strength at room temperature and about 900 N/mm2 at 315 degC | Ti-Mo binaries lose ductility when aged or cast (Ti-15.05Mo falls to 6.95 % elongation after solution treatment), and Ti-Ga, Ti-Si and Ti-V have no alloy-level property value in the sources read |
| Copper (Cu) | Carrying electricity and heat: 100 %IACS electrical conductivity and 391 W/(m·K) thermal conductivity in the soft oxygen-free grade | Strength in the soft state (69 MPa yield), and survival of the cell's copper foil if the cell is over-discharged (dissolution above about 3.5 V vs Li+/Li in a model) |
| Free-cutting brass C36000 | High-volume machined parts such as screw-machine products, fasteners and valve components, where machinability rated 100 matters most | Corrosion in water (dezincification, about 35 % zinc) and in ammonia (season cracking), plus its 2.5 to 3.0 % lead content |
| Aluminium bronze C95400 | Heavily loaded, low-speed bearings, worm gears and valve parts, and marine hardware in seawater (Concast, Bunting, Wikipedia) | Dealuminification in seawater crevices, under deposits or with galvanic coupling, and oxyacetylene welding (not recommended by Concast) |
| Aluminium bronze C63000 | Highly loaded, wear-resistant bearings and worm wheels, aerospace landing gear parts, marine fasteners, and pump and valve parts (Smith Metal, Zollern) | Brazing and soft soldering (Zollern), dealuminification in crevices or under deposits, and sulphide-polluted sea water (Hendrix) |
| Beryllium copper (BeCu) | High strength with useful conductivity and non-magnetic behaviour in springs, bushings, bearings and connectors, once beryllium exposure is controlled | Health: beryllium dust, mist and fume are a serious inhalation hazard. Strength also depends on temper, since annealed stock yields at only 130 to 250 MPa |
| C510 | Springs and electrical contacts: H08 spring temper has a minimum tensile strength of 790 MPa in fine round sizes (Concast), and the alloy solders and brazes well | Dust and fume when cut, ground or welded (Fisk SDS); a seawater corrosion rate for C51000 was not found in this run |
| Cartridge brass 70/30 (C260) | Cold-formed and deep-drawn parts such as cartridge cases, fasteners, pins and radiator parts, where good cold working and a ductile temper matter most | Season cracking in ammonia or amine atmospheres when residual stress from cold forming is left in the part |
| Cu-Ag | Conductors that must stay conductive and resist softening after repeated heating, such as commutators and generator rotor bars | Strength as-cast (180 N/mm2 rod); density, melting point and thermal conductivity for this grade could not be read from a fetched source |
| CuCrZr | Parts that must carry current or heat and keep strength under repeated heating, such as welding electrodes and high-heat-flux liners | Overheating: the hardened condition is lost near 500 °C, and the alloy is not resistant to ammonia, halide, cyanide, sulphide or seawater exposure |
| Cupronickel 70/30 (CuNi 70/30) | Seawater condenser, heat-exchanger and piping parts, where resistance to seawater matters more than strength or service temperature | Strength and rated temperature: soft rod gives 358 to 414 MPa, no maximum service temperature is printed, and sulphide-rich seawater still corrodes it at about 0.09 mm/a in the laboratory test |
| CW614N | Machined parts in volume (screw-machine products, fittings, fasteners) where machinability and a standard reference grade matter most | Ammonia and acid exposure, stress corrosion cracking after cold work, and potable-water use, all made worse by its 2.5 to 3.5 % lead and about 39 % zinc |
| Nickel silver C75200 | Springs, connectors and precision optical or watch parts that need a silver colour, cold-formed strength and corrosion resistance without precious metal | Machinability (Fisk rates it 1 of 5, Matthey calls it rather poor) and hot working, plus the nickel content, which carries allergy and carcinogen hazard statements |
| Phosphor bronze C52100 (CuSn8) | Springs and connectors: the H08 spring temper has 725 to 820 MPa tensile strength and 690 MPa minimum yield (Aurubis), and the alloy solders and brazes excellently | Dust and fume when cut, ground or welded (Fisk SDS); the only seawater corrosion rate read is an unnamed-test manufacturer claim (jtcopper) |
| C655 | Welded tanks, pressure vessels, pump and valve parts, and marine hardware where welding and corrosion resistance matter more than conductivity | Electrical conductivity of 7 %IACS, and not recommended above 150 degC or in steam above 100 degC (Australwright datasheet) |
| Tellurium copper (Cu-Te) | Free-machining electrical parts that need copper-level conductivity: 93 % IACS with a machinability rating of 85 | Corrosion data and dust safety: no quantitative corrosion test was found, and machining releases tellurium-bearing dust |
| Tinned copper (Sn/Cu) | Solderable, heat-conducting current paths in shields and harnesses: a 58 MS/m copper core with a tin skin, and tin-plated braid rated -65 to +150 °C | Cold and whiskers: tin turns brittle below 13.2 °C, and pure tin plate can grow whiskers several millimetres long that bridge closely spaced circuits |
| Inconel 718 | Hot and cryogenic structural parts that must keep strength and fatigue resistance, such as rocket engine shells, rings, casings and fasteners | The datasheet service limit is 1300 F, and long exposure between about 700 and 1000 C lets delta phase form and weaken the alloy |
| Inconel 625 | Corrosion-resistant parts that also need strength and good weldability, such as chemical plant, marine hardware, aerospace ducting and rocket tubing | Long exposure near 1200 F hardens the annealed alloy and cuts its room-temperature elongation from 54 to 30 percent after 2000 hours |
| Hastelloy B-3 (Ni-Mo) | Hot hydrochloric and sulfuric acid service in reducing conditions: 0.29 mm/y in boiling 20 % HCl and 0.03 mm/y in boiling 50 % H2SO4 in Haynes lab tests | Oxidising conditions: ferric or cupric salts, wet chlorine gas and hypochlorite bleach (no chromium to protect it), and cracking in welds after more than about 7 % cold work without re-annealing |
| Hastelloy C-22 | Resisting pitting and crevice corrosion in hot chloride, oxidizing and mixed acid environments, including seawater, in the solution-annealed condition | Long exposure at 593 to 760 °C, where mu phase forms on grain boundaries and ductility falls, and hot hydrochloric acid, which corrodes it at more than 10 mm/y when boiling |
| Hastelloy C-276 | Wet, mixed-acid and chloride service where a corrosion-resistant nickel alloy must also be welded and formed (Haynes; ATI) | Hot, concentrated nitric acid, where ATI says the chromium content is too low; Haynes gives 22.12 mm/y at the boil in 65 percent nitric acid |
| Hastelloy X | Hot oxidising gas and furnace service where the alloy must also be formed and welded: metal loss of 0.007 mm per side after 1008 h at 980 C in flowing air (Haynes) | Strength at high temperature and after long ageing: plate yield falls from 340 MPa at room temperature to 189 MPa at 871 C (Haynes), and Charpy energy falls from 129 J to 16 J after 16,000 h at 871 C (Haynes) |
| Haynes 214 (UNS N07214) | Static, low-stress parts in hot oxidising gas, such as furnace belts, flame hoods, honeycomb seals and combustor splash plates, where oxidation or scale loss above 1750 °F is the limit | Strength above about 1800 °F, where sheet UTS falls to 68 MPa, and welding of restrained parts through the 595 to 925 °C range, where gamma-prime precipitation can cause strain-age cracking |
| Haynes 230 | Hot-gas parts that must resist oxidation to 2100 °F (1149 °C) and keep strength, such as gas turbine combustion cans, transition ducts and flame holders | Hydrogen service (a 2022 NASA trade study rates its hydrogen embrittlement risk high) and long exposure at 1400 °F (760 °C), which cuts room-temperature elongation to 32 % after 8,000 h |
| Incoloy 800 (UNS N08800) | Strength and oxidation resistance up to about 816 °C (1500 °F), with resistance to chloride stress-corrosion cracking | Creep and rupture strength above about 816 °C, where the bulletin points to alloys 800H and 800HT, and sensitisation after heating at 540 to 760 °C |
| Incoloy 825 | Corrosion service in sulfuric and phosphoric acid, sour gas and seawater, in sheet, plate, bar, tube and pipe that must be welded and formed | Strength against chloride pitting: Jacquet judges it only an improvement over Type 316 for pitting, and rates Alloy 625 and AL-6XN higher |
| Inconel 600 | Hot or cryogenic-to-hot parts in oxidising and corrosive chemical service where chloride stress-corrosion cracking must be avoided, such as furnace parts, heater sheaths, electronic support parts and springs | Strength in the annealed state (170 to 345 MPa yield, so cold work is needed for more), and sensitization between 540 and 760 °C, which makes it prone to intergranular attack; it also cracks in high-temperature, high-strength caustic alkali unless stress-relieved |
| Inconel 601 (Alloy 601) | Hot furnace parts and oxidising heat: resistance to high-temperature oxidation up to about 1200 °C, with strength that holds up well in the annealed condition | Carbon pickup in carburizing and carbonitriding atmospheres (16.66 mg/cm2 gain in 100 h at 1095 °C in one test), and the sources give no spacecraft or vacuum data |
| Inconel 617 (Alloy 617) | Hot parts that must keep strength and resist oxidation above 1800 °F (982 °C), such as gas-turbine combustion cans, ducting and transition liners | Nickel content: the main element is nickel (PubChem notifications classify nickel as a sensitiser and suspected carcinogen), and the alloy loses ductility after long exposure at 650 °C |
| Inconel X-750 | Springs and high-strength fasteners that must keep their load from sub-zero temperatures to 1200 F, where relaxation resistance matters | Weight (8.28 g/cm3), and the strength depends on the temper: the spring-temper wire relaxes about four times as much as the No. 1 temper at 800 F, and welding a precipitation-hardened part can crack the parent metal |
| Kovar (Fe-Ni-Co) | Hermetic glass-to-metal seals: a mean expansion coefficient of 5.25 ×10⁻⁶/°C from 25 to 450 °C, close to borosilicate glass | Heat conduction and weight: 17.5 W/m °K at 20 °C and a density of 8.36 g/cm3, and a yield strength of only 200 MPa minimum when annealed |
| Monel 400 | Seawater, hydrofluoric-acid and reducing-acid service, and marine valves, pump shafts and fasteners, where corrosion resistance matters more than high strength | Stagnant seawater (crevice and pitting corrosion), caustic at high temperature and stress (stress-corrosion cracking), and low strength in the annealed condition |
| Monel K-500 | Springs, fasteners and pump parts that need much higher strength than Monel 400 with similar corrosion resistance, in a virtually non-magnetic alloy | Stress corrosion cracking in the age-hardened condition, which is the condition that gives the high strength |
| Nickel | A tough, corrosion-resistant, magnetic metal that conducts heat and electricity and can be applied as a plated barrier coating | Skin sensitisation and cancer-hazard concerns for people, and no space-environment test data found in this record (no outgassing, atomic-oxygen or flight results) |
| Nickel aluminide | High-temperature strength and oxidation resistance for turbine parts and hot-section coatings, where the material is run inside its stated temperature range | Lower ductility of stoichiometric NiAl (NASA), no sourced ductility value for Ni3Al, and no sourced melting point or flight record for either compound |
| Nimonic 90 | High-temperature strength and creep resistance up to about 920 °C, for turbine blades, discs, forgings and ring sections | Weight (8.18 g/cm3), hard machining (250 to 350 HV when fully heat treated), and oxide spalling under cyclic heating (onset after 250 h at 990 °C) |
| Waspaloy (UNS N07001) | Hot rotating and static parts that must keep strength to about 650 °C in critical rotating use and to 870 °C in less demanding use: discs, shafts, casings, fasteners and rocket turbopump blade rotors | Weldability and forming: the alloy is hot short, prone to strain cracking and work hardens rapidly, and its welds are weaker than the wrought material at high temperature |
| Zinc and zinc alloys (Zn) | Die-cast parts with thin walls, and steel protected by a galvanised zinc coating | Weight (6.3 to 7.2 g/cm3) and post-casting shrinkage in precision die castings |
| Zamak | Thin-walled die-cast parts, and heat sinks and EMI shields that need good heat and electrical conduction | Creep under sustained load (Zamak 3 creeps most of the four grades the IZA tests), and intercrystalline corrosion when tin or lead exceed the specified limits |
| Zinc minor alloys | Thin rolled zinc roofs, facades and gutters, and steel sheet coated with Zn-Al-Mg where cut edges and chloride air matter | The corrosion figures for zinc-nickel and Zn-Al-Mg come from a plater, a coating maker and a literature summary, not from a standard test report, and no corrosion data for the rolled sheet was read in this run |
| Magnesium alloy AZ31B | Light wrought sheet, plate and extrusions where weight matters and the part is kept out of chloride solutions. The stockist names aircraft fuselages and phone and laptop cases as uses. | Corrosion in chloride solutions (uncoated AZ31: 0.27 mm per year in 3.5 % NaCl and 9.7 mm per year in 5 M NaCl), and fire risk from magnesium metal (GHS statements for the element). |
| Magnesium (pure metal) (Mg) | Light, unalloyed magnesium for research and for alloying or reducing use, such as Kroll-process titanium production and magnesium-ion battery anode research, where the purity matters more than structural strength. | Strength and corrosion resistance. Goodfellow gives 140 to 160 MPa tensile strength for pure magnesium against 260 MPa for wrought AZ31, and says chlorides break down the passive film. Powder and ribbon are pyrophoric. |
| Magnesium alloy AZ61 | Forged structural parts such as aircraft mounts, made from a cast preform and kept out of salt water (the 2021 study forged this way) | Corrosion in chloride solutions (the readable sources give trends, not an AZ61 rate), and fire risk from magnesium metal (element-level GHS statements) |
| Tungsten (W) | Very high temperature parts, dense counterweights and gamma shielding where weight per unit of shielding matters more than cost | Brittle and hard to form or machine; oxidises in air when hot, so it needs protection above room temperature |
| Tantalum | Dense, high-melting spot shielding in thin sheet, such as the approximately 1 mm tantalum vault plate on NASA's Europa Clipper | Mass: the 16650 kg/m3 density makes it heavy for large areas, and the vault plate is only a local shield, not a full enclosure |
| Hafnium (Hf) | Absorbing neutrons in reactor control rods (104 barns thermal neutron cross-section) and strengthening nickel superalloys (ATI) | Fine powder and chips, which ignite in air (ATI, ESPI), and strength that depends strongly on oxygen, nitrogen and carbon pickup (ATI) |
| Molybdenum | High-temperature strength and heat conduction: 2623 °C melting point and 142 W/(m·K) thermal conductivity at 20 °C, in vacuum or inert service | Oxidation in air above about 400 °C, where it forms volatile MoO3, and toughness at room temperature in as-rolled sheet (ductile-brittle transition above 25 °C in the NASA study) |
| Mo-Re | Structural and cladding use at high temperature in vacuum or inert gas, for example fuel cladding and core structures in space reactors, where ductility must survive welding | Oxidation in air above about 600 °C, and embrittlement by the sigma phase in Mo-47.5Re and by irradiation above about 1100 K |
| TZM molybdenum alloy | High-temperature strength in vacuum and inert furnaces: recrystallisation at 1400 °C and a reference yield strength of 750 to 900 MPa, against 1100 °C for pure molybdenum | Oxygen and water vapour. TZM loses ductility at 500 ppm oxygen and is embrittled within hours at 1150 °C in low-pressure oxygen (ORNL-5431), so it is kept below 825 °C in oxidising service |
| Niobium (Nb) | Hot structures that must hold stress above 1000 °C: C-103 keeps a minimum yield strength of 124 MPa at 1093 °C in vacuum (Smiths datasheet, minimum values) | Oxidation in air: niobium begins to oxidise at 200 °C, and unprotected C-103 needs a coating above 800 °C. C103 is expensive because of its hafnium content (NASA Glenn), and the USGS reports 100 % net import reliance for the United States. |
| Niobium alloys (Nb alloys) | Hot load-bearing nozzles: C-103 keeps a minimum yield strength of 124 MPa at 1093 °C in vacuum (Smiths datasheet, minimum values) | Oxidation in air: all three need a protective coating above about 400 °C (Wikipedia). Niobium supply is concentrated in Brazil, which mines about 93 % of world niobium (USGS 2026). |
| Rhenium (Re) | Structures that must hold strength above 2000 °C: iridium-coated rhenium thrust chambers tested up to about 2200 °C | Oxidation in air or oxygen-rich gas above about 300 °C, which makes uncoated rhenium unusable without a protective coating |
| Tungsten-rhenium alloys (W-Re) | High-temperature thermocouples and X-ray target tracks, used in reducing, inert or vacuum conditions where pure tungsten is too brittle | Rapid oxidation at high temperature in air or other oxidising gas (the data sheet says not recommended there) |
| Tungsten heavy alloy (WHA) | Dense, stiff parts that must absorb X-rays and gamma rays, or sit as counterweights in a small volume (density 16.85 to 18.85 g/cc across ASTM B777 classes 1 to 4) | Ductility falls as tungsten rises: minimum elongation is 2 % in class 4. The binder contains nickel, a hazardous substance. No vacuum or flight result was found. |
| Tungsten-copper (W-Cu) | Heat sinks and electrical contacts: a thermal conductivity of 235 W/(m·K) at 20 °C with a low thermal expansion of 8.3 ppm/K in the Plansee WCu20 grade | Heavy, and it oxidises in hot air: density 15.15 g/cm3 for W80Cu20, and strong oxidation in air beginning around 400 °C |
| Vanadium | Alloying steel and aerospace titanium: no acceptable substitute exists for vanadium in aerospace titanium alloys (USGS 2026) | Fire and oxidation: fine powder is pyrophoric and bulk metal ignites above about 600 °C in air, and the oxide V2O5 is toxic (Goodfellow) |
| Vanadium alloys (V alloys) | Fusion first-wall and blanket structures that must carry load at high temperature with low activation (Argonne) | Oxygen and hydrogen pickup: the alloy embrittles after exposure to oxygen at 500 to 700 C, and vanadium-based membranes are highly susceptible to hydrogen embrittlement |
| Zirconium and Zircaloy (Zr) | Corrosion resistance in acids, especially hot nitric acid: 0.0 mpy for Zr 702 in 65 % nitric acid at 204 °C (ATI nitric acid sheet, Table 1) | Dry powder fire risk, delayed hydride cracking of Zircaloy cladding, and loss of strength when hot (Zr 702 yield 97.2 MPa at 316 °C) |
| Titanium hydride (TiH2) | Hydrogen reservoirs and foaming agents for metal powder processing (Albemarle grade N and the KTU aluminium foam paper), and zirconium hydride as a moderator with a high moderating ratio (ORNL Table 1) | Hydrogen loss on heating: TiH2 releases hydrogen from about 763 K, ZrH2 evolves hydrogen above 300 °C (ATI), and all three powders are flammable with a dust-explosion risk |
| Beryllium | Stiff, light structures and mirrors that must hold their shape when cold: 290 GPa modulus at 1.85 g/cm3 in the pure S-65 grade | Toxicity: inhaled dust or fume causes chronic beryllium disease, and the metal is hard and brittle with 3.0 % minimum elongation |
Where each is used
| Material | Use |
|---|---|
| A36 structural carbon steel | General construction and structural framing |
| A36 structural carbon steel | Girders, structural shapes and angle iron |
| A36 structural carbon steel | Bolted and welded structural joints |
| Carbon steel 1018 | Shafts, pins and gears |
| Carbon steel 1018 | Low-stress structural components |
| Aluminium alloy 6061 | Launch vehicle and spacecraft structures (aluminium alloys, 6061 named as a structural alloy) |
| Aluminium alloy 6061 | Simulated propellant tanks of 6061-T3 sheet (ground impact tests, not flown) |
| Aluminium alloy 6061 | Fittings, couplings, hinge pins, valves and valve parts, and hydraulic and brake pistons |
| Aluminium alloy 7075-T6 | Aircraft structures and airframe parts |
| Aluminium alloy 7075-T6 | High-pressure hydraulic units |