Carbon steel 1070 1070 (UNS G10700, AISI 1070, SAE 1070)

Iron with 0.65 to 0.75 % C, 0.60 to 0.90 % Mn, max 0.040 % P, max 0.050 % S and max 0.100 % Si (wt %)

Also known as UNS G10700, EN 1.1231, AISI 1070, SAE 1070, SAE J403, AFNOR XC 68 · 5 more

AISI / SAE 1070 is a plain high-carbon steel (UNS G10700) with 0.65 to 0.75 percent carbon and 0.60 to 0.90 percent manganese.

11 sources · Updated 2026-10-25 · CC BY 4.0

Evidence level

2 of 5

Lab-measured

Carry load

640 to 700 MPa tensile

Hardness

192 to 212 HB

Stiffness

190 to 210 GPa

Weight

7.7 to 8.03 g/cm3

Heat conduction

50 W/(m·K)

Recipe, share of the weight

  • Fe balance of the composition (Gravity Cast: Iron, Fe, balance)Iron
  • C 0.65 to 0.75%Carbon
  • Mn 0.6 to 0.9%Manganese
  • P maximumPhosphorus
  • S maximumSulphur
  • Si maximum (Gravity Cast)Silicon

Best for

Springs, shafts and hand tools that are heat treated and kept dry or coated (tensile strength 640 to 700 MPa in the supplier range)

Weakest at

Corrosion, which is poor without a coating, brittleness once fully hardened, and poor weldability

Risk at a glance

  • People Low. Fume and dust hazard
  • If it fails Moderate. Brittle fracture after full hardening
  • Corrosion No data. No corrosion data recorded

Quick facts: 1070 (UNS G10700, AISI 1070, SAE 1070)

Key properties of 1070 (UNS G10700, AISI 1070, SAE 1070)
PropertyValueBasis
Density7.7 to 8.03 g/cm³2 sourced values across conditions
Yield strength390 to 495 MPa2 sourced values across conditions
Tensile strength640 to 700 MPa2 sourced values across conditions
Young's modulus190 to 210 GPa1 sourced value
Hardness (Brinell)192 to 212 HB2 sourced values across conditions
Thermal conductivity50 W/(m·K)1 sourced value
Thermal expansion (CTE)11.8 ppm/K1 sourced value
Specific heat470 J/(kg·K)1 sourced value

What is the density of Carbon steel 1070?

Carbon steel 1070 has a density of 7.7 to 8.03 g/cm³. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What is the thermal conductivity of Carbon steel 1070?

Carbon steel 1070 has a thermal conductivity of 50 W/(m·K). The source and test conditions are listed in the properties table on this page.

What is the coefficient of thermal expansion of Carbon steel 1070?

Carbon steel 1070 has a coefficient of thermal expansion of 11.8 ppm/K. The source and test conditions are listed in the properties table on this page.

What is the yield strength of Carbon steel 1070?

Carbon steel 1070 has a yield strength of 390 to 495 MPa. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What is the tensile strength of Carbon steel 1070?

Carbon steel 1070 has a tensile strength of 640 to 700 MPa. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What are the other names and codes for Carbon steel 1070?

Carbon steel 1070 is also written as UNS G10700, EN 1.1231, AISI 1070, SAE 1070, SAE J403, AFNOR XC 68. Each code is printed in the source listed beside it in the designations table.

What is Carbon steel 1070 used for?

Uses recorded in the sources include Springs and shafts; Valve, pump and general engineering parts; Railroad and street railway rails, heavy machinery parts.

Why it exists

AISI/SAE 1070 is a plain high-carbon steel, about 0.7 percent carbon. Its strength comes from its carbon content and heat treatment. Supplier data give a tensile strength of 640 to 700 MPa and a Brinell hardness of 192 to 212 HB. Wikipedia notes that high-carbon steel is used where medium strength and low material cost matter. Its weak points are rust, brittleness once fully hardened, and poor weldability.

Where it's used

Springs and shafts

The Wikipedia spring steel table lists 1070 as a common spring grade. The knife-supplier page quotes the application list for SAE 1070: railroad rails, heavy machinery parts, shafts, springs and a wide variety of hand and machine tools.

Valve and pump parts

Gravity Cast says the grade is intended for valve, pump, general engineering, automotive and other industries.

Rails and heavy machinery

The knife-supplier page lists railroad and street railway rails and heavy machinery parts among the uses of SAE 1070.

Recipe

Iron with 0.65 to 0.75 % C, 0.60 to 0.90 % Mn, max 0.040 % P, max 0.050 % S and max 0.100 % Si (wt %)

Plain carbon steel of iron with 0.65 to 0.75 % carbon and 0.60 to 0.90 % manganese, with maximum phosphorus 0.040 %, sulphur 0.050 % and silicon 0.100 % (Gravity Cast, Alro). It is supplied as bar, wire rod, plate, strip, sheet or tube (Gravity Cast product list). Process steps beyond these product forms were not found in a fetched source.

What 1070 (UNS G10700, AISI 1070, SAE 1070) is made of
IngredientShare of the weightWhat it does
Iron Fe balance of the composition (Gravity Cast: Iron, Fe, balance) Matrix of the steel
Carbon C 0.65 to 0.75% Lets the steel harden and strengthen by heat treatment (Wikipedia carbon steel article)
Manganese Mn 0.6 to 0.9% Specified alloying element; no role stated in the fetched sources
Phosphorus P maximum Impurity limit
Sulphur S maximum Impurity limit
Silicon Si maximum (Gravity Cast) Impurity limit

Weight shares are as printed in the sources.

What it can do

Carry load

640 to 700 MPa tensile

The supplier range is 640 to 700 MPa tensile strength, with yield at least 390 MPa. A materials database gives 495 MPa yield for the same grade with no condition printed.

Hardness

192 to 212 HB

measured

Brinell hardness is 192 to 212 HB in the supplier range, and 192 HB at 25 °C in the cold drawn, spheroidized annealed condition.

Stiffness

190 to 210 GPa

measured

The elastic modulus of cold drawn AISI 1070 is 190 to 210 GPa, according to the AZoM property table.

Weight

7.7 to 8.03 g/cm3

measured

Density is 7.7 to 8.03 g/cm3 in the AZoM table, and 7850 kg/m3 in the Matmake table.

Heat conduction

50 W/(m·K)

measured

Matmake gives a thermal conductivity of 50 W/(m·K), with no temperature stated.

Expansion

11.8 10-6/°C

measured

The coefficient of thermal expansion is 11.8 10-6/°C over 0 to 100 °C, according to the AZoM thermal table.

How it compares

Among the plain carbon steels, 1070 is the high-carbon grade with a 0.65 to 0.75 percent carbon range, which is what lets it harden for springs. The sources in this profile do not give a side-by-side number from another grade, so the table rows below read the 1070 values only, and any comparison with a different carbon steel needs that grade's own profile.

The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.

Benchmarks
Measurement1070 (UNS G10700, AISI 1070, SAE 1070)A36 (UNS K02600)1018 (UNS G10180, AISI 1018)1045 (UNS G10450, AISI 1045)1215 (UNS G12150, AISI 1215)4130 (UNS G41300)4140 (UNS G41400)1010 (UNS G10100, AISI 1010)4340 (UNS G43400)
Thermal behavior and safety
Thermal conductivity, SAE/AISI 107050 W/(m·K)5no data51.9 W/m-Kno data51.9 W/m-K42.7 W/m-K42.6 W/mK64.21 W/(m∙°C)no data
Specific heat capacity, SAE/AISI 1070470 J/(kg·K)6no data0.486 J/g-°Cno data0.472 J/g-°C0.477 J/g-°C0.473 J/gK450 J/(kg·K)no data
Physical and electrical
Density, AISI 1070 (range)7.7 g/cm³17.8 g/cm³7.87 g/ccno data7.87 g/cc7.85 g/cc7.85 g/cc7.9 g/cm³7.7 to 8.03 g/cm³
Density, SAE/AISI 10707850 kg/m327.8 g/cm³7.87 g/ccno data7.87 g/cc7.85 g/cc7.85 g/cc7.9 g/cm³7.7 to 8.03 g/cm³
Brinell hardness, supplier rangeRange printed in a supplier data sheet192 HBno datano datano data167 HB197 HB269 to 331 HBno data248 to 302 HB
Brinell hardness, cold drawn and spheroidized annealed AISI 1070192 HB10no datano datano data167 HB197 HB269 to 331 HBno data248 to 302 HB
Temperature behavior
Hardening temperature, knife-supplier schedule800 °C11no datano datano datano datano datano datano datano data
Tempering temperature range, knife-supplier schedule175 °C12no datano datano datano datano datano datano datano data
Annealing temperature, knife-supplier schedule741 °C13no datano datano datano datano datano datano datano data
Other measurements
Elastic modulus, cold drawn AISI 1070 (range)190 GPa3200 GPa200 GPa190 to 210 GPa200 GPa205 GPa205 GPa210 GPa190 to 210 GPa
Coefficient of thermal expansion, AISI 107011.8 10-6/°C4no datano datano data11.5 µm/m-°C6.2×10^-6 1/F12.2 ppm/Kno data11.5 ppm/K
Tensile strength, AISI 1070 (supplier range)Range printed in a supplier data sheet640 MPa58 to 80 ksi440 MPa> 690 MPa540 MPa820 MPa930 to 1080 MPa350 MPa850 to 1000 MPa
Tensile strength, cold drawn and spheroidized annealed AISI 1070640 MPa758 to 80 ksi440 MPa> 690 MPa540 MPa820 MPa930 to 1080 MPa350 MPa850 to 1000 MPa
Yield strength, supplier minimumMinimum value printed in a supplier data sheet> 390 MPa8> 36 ksi370 MPa> 540 MPa415 MPa635 MPa> 740 MPa190 MPa> 665 MPa
Yield strength, AISI 1070495 MPa9> 36 ksi370 MPa> 540 MPa415 MPa635 MPa> 740 MPa190 MPa> 665 MPa
Elongation, supplier minimumMinimum value printed in a supplier data sheet> 10 %> 21 %15 %> 8 %10 %25.5 %> 12 %30 %> 13 %
Reduction of area, supplier rangeRange printed in a supplier data sheet30 %no data40 %no data35 %67 %46.8 %no datano data

Why choose it, and why not

Good for

  • Springs and shafts, after heat treatment: the grade is listed for springs and shafts by a knife supplier and a spring steel table.
  • Low-cost plain steel parts for valves, pumps and general engineering, per the Gravity Cast application line.
  • Tools and rails that need strength and wear resistance, per the knife-supplier application list.

Watch out for

  • Rust: carbon steel rusts in moist or salty air, and no 1070-specific corrosion rate was found.
  • Brittleness: fully hardened steel is brittle, and the tempering range from one supplier is 175 to 200 °C.
  • Welding: high-carbon steel has poor weldability (Wikipedia).
  • Yield strength differs between sources (390 MPa supplier minimum, 495 MPa database value).

AISI/SAE 1070 is a plain high-carbon steel with a tensile strength of 640 to 700 MPa and a hardness of 192 to 212 HB in the supplier range. It works as a spring and shaft steel once heat treated, but it rusts without a coating, is brittle when fully hardened, and welds poorly. No space-environment data or 1070-specific corrosion rate was found in the sources.

Technical details

For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.

Other names and standards

The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.

Other names and standards
SystemCodes
UNSG10700
EN1.1231 (listed as equivalent to AISI 1070)
AISI1070
SAE1070, J403 (chemical composition specification)
AFNORXC 68
SS1770
ASTMA510 (wire rod and round wire), A830 (plate and steel)
ASMESA-29 (grade 1070)
AMS5115

Notes

The method, full conditions and any caveat for the numbered rows above.

Notes for the numbered rows
#MeasurementMethodConditionsCaveat
1Density, AISI 1070 (range)Range printed in a materials encyclopedia property tablegrade AISI 1070temperature not statedunit in source 7.7-8.03 g/cm3 (0.278-0.290 lb/in3)—
2Density, SAE/AISI 1070Value printed in a materials database property tablegrade SAE/AISI 1070temperature not stated—
3Elastic modulus, cold drawn AISI 1070 (range)Range printed in a materials encyclopedia property table under the heading cold drawn AISI 1070form cold drawntemperature not statedunit in source 29700-30458 ksi—
4Coefficient of thermal expansion, AISI 1070Value printed in a materials encyclopedia thermal property tabletemperature 0 to 100 °Ctreatment not stated—
5Thermal conductivity, SAE/AISI 1070Value printed in a materials database thermal property tabletemperature not stated—
6Specific heat capacity, SAE/AISI 1070Value printed in a materials database thermal property tabletemperature not stated—
7Tensile strength, cold drawn and spheroidized annealed AISI 1070Value printed in a materials database property tabletemperature 25 °Ccondition cold drawn, spheroidized annealed—
8Yield strength, supplier minimum—temperature not statedcondition not specified in the tableA materials database gives 495 MPa for the same grade with no condition printed (next entry). The two are not reconciled.
9Yield strength, AISI 1070Value printed in a materials database property tabletemperature not printedcondition not printed—
10Brinell hardness, cold drawn and spheroidized annealed AISI 1070Value printed in a materials database property tabletemperature 25 °Ccondition cold drawn, spheroidized annealed—
11Hardening temperature, knife-supplier scheduleHeat treatment schedule printed on a knife-supplier page, not a mill or standard specificationhold 10 minutesquench PQ11 fast oilgrade SAE 1070—
12Tempering temperature range, knife-supplier scheduleHeat treatment schedule printed on a knife-supplier page, not a mill or standard specificationgrade SAE 1070—
13Annealing temperature, knife-supplier scheduleHeat treatment schedule printed on a knife-supplier page, not a mill or standard specificationhold 30 minutes, then slow cool in furnace, ash or vermiculitegrade SAE 1070—

Corrosion and compatibility

What happens when it meets other materials and environments.

Corrosion and compatibility
EnvironmentConcernWhat happens
Moist or salty air, uncoated not rated Carbon steel rusts in moist or salty air, and a coating such as paint or varnish shields it.1
Corrosion details
#EnvironmentDetailsTest conditions
1 Moist or salty air, uncoated The Wikipedia carbon steel article says carbon steel is susceptible to rust and corrosion, especially with high moisture and/or salt. No corrosion rate or 1070-specific rating was found in a fetched source. basis general statement for carbon steel, not measured on 1070

Risks and side effects

Hazards to people, what happens when a cell overheats, and how the material is handled and stored.

For people

The solid steel is not classed as hazardous. The hazards come from fume and dust made when it is cut, ground, melted or welded.

Solid steel
Metals Depot's steel safety data sheet calls steel an article that is not hazardous in its solid form.
Cutting and welding
The same sheet gives GHS classes for the fume: carcinogenicity Category 1B, respiratory sensitizer Category 1 and skin sensitizer Category 1. It is a generic steel sheet, not a 1070 sheet.

If it fails

These are failure routes found in the sources. None is a measured 1070 test result.

Brittle when hardened
Quenched carbon steel is extremely hard but brittle, usually too brittle for practical purposes (Wikipedia). Tempering at 175 to 200 °C is the schedule a knife supplier quotes.
Rust
Carbon steel is susceptible to rust, especially in moist or salty air. Paint, varnish or another coating shields it.

Handling and storage

Supply condition
The Wikipedia spring steel table says 1070 is normally supplied annealed. The annealed supplier range is 192 to 212 HB.
Heat treatment
A knife supplier anneals at 741 °C, hardens at 800 °C for 10 minutes, quenches in PQ11 fast oil and tempers at 175 to 200 °C. This is not a mill specification.

Test details
The original wording and numbers from the sources, for readers who want them.

Failure risks

Failure risks
FailureTrigger and consequence
Brittle fracture after full hardeningmoderate severitySteel hardened and not tempered; the knife-supplier schedule hardens at 800 °C, quenches in PQ11 fast oil, then tempers at 175 to 200 °CQuenched carbon steel is extremely hard but brittle, usually too brittle for practical purposes (Wikipedia). The source gives no fracture data for 1070.
Rust in moist or salty servicemoderate severityUncoated steel left in humid air or in saltCarbon steel is susceptible to rust and corrosion. The source names paint, varnish or another protective material as the shield.
Poor weldabilitylow severityWelding high-carbon steelHigh-carbon steel has extremely poor ductility and weldability (Wikipedia carbon steel article, Higher-carbon steels section).

Handling and storage

  • Heat treatment schedule from a knife supplier: anneal at 741 °C and slow cool, harden at 800 °C for 10 minutes and quench in PQ11 fast oil, temper at 175 to 200 °C.
  • Normally supplied annealed, according to the Wikipedia spring steel table, row 1070.
  • Do not breathe dust, fume, gas, vapour or spray from cutting, grinding or welding, and use in a well-ventilated area.

Supply and geography

How common the raw materials are and where they come from.

Raw steel production, 2025 estimate

Iron is the least expensive and most widely used metal (USGS). World raw steel production in 2025e is 1,900 million t, rounded. Printed country values in million t: China 980, India 160, Japan 81, United States 82.

Substitutes
USGS: iron and steel compete with aluminum and plastics in automotive, with aluminum, concrete and wood in construction, and with aluminum, glass, paper and plastics in containers.