spore: profile id: silicon-bronze spore_version: 0.2 family: copper-alloys name: Silicon bronze C65500 (CuSi3Mn1) abbreviation: C655 role: wrought copper-silicon-manganese alloy for welded vessels, fasteners, bushings and marine hardware category: metals type: copper-alloys summary: | Silicon bronze C65500 (UNS C65500, EN CW116C, EN name CuSi3Mn1, also called Everdur in the US and Cusilman in Australia) is a wrought copper alloy with 2.8 to 3.8 % silicon and 0.50 to 1.3 % manganese, and copper as the remainder. Its density is 8.53 g/cm3 and its electrical conductivity is 7 %IACS, so silicon lowers its conductivity to about that of steel. The H02 flat product in the datasheet has a tensile strength of 538 MPa and a yield strength of 310 MPa, and the H08 temper reaches 758 MPa. The datasheet rates it highly for corrosion in industrial, marine and rural air and in stagnant sea water, and it is one of the easiest copper alloys to weld. best_for: Welded tanks, pressure vessels, pump and valve parts, and marine hardware where welding and corrosion resistance matter more than conductivity weakest_at: Electrical conductivity of 7 %IACS, and not recommended above 150 degC or in steam above 100 degC (Australwright datasheet) identity: formula: 'Cu-Si-Mn wrought single-phase alloy, UNS C65500: copper matrix with 2.8 to 3.8 wt % silicon and 0.50 to 1.3 wt % manganese; iron 0.8 max, zinc 1.5 max, nickel 0.6 max, lead 0.05 max (wt %)' source: australwright-c65500 where: Chemical Composition table (Min/Max column); Introduction paragraph naming UNS C65500; Wikipedia Bronze article gives the same silicon, manganese, iron, zinc and lead limits designations: - system: UNS code: C65500 source: australwright-c65500 where: Introduction paragraph, sentence beginning International this alloy is known as UNS C65500 - system: EN name code: CW116C source: wieland-c65500 where: Specifications of Bronze CDA 65500, International Standards table, Europe row - system: EN name code: CuSi3Mn1 source: wieland-c65500 where: Specifications of Bronze CDA 65500, International Standards table, Europe row - system: EN code: '2.1525' source: wieland-c65500 where: Specifications of Bronze CDA 65500, International Standards table, Germany row (DIN 17666, name CuSi3Mn) - system: BS code: CS 101 source: wieland-c65500 where: Specifications of Bronze CDA 65500, International Standards table, UK row - system: GOST code: BrKMc3-1 source: wieland-c65500 where: Specifications of Bronze CDA 65500, International Standards table, Russia row - system: GB code: QSi3-1 source: wieland-c65500 where: Specifications of Bronze CDA 65500, International Standards table, China row - system: ASTM code: B98 note: rod and bar source: australwright-c65500 where: Applicable Specifications table, Rod and Bar rows - system: ASTM code: B96 note: sheet, plate and strip source: australwright-c65500 where: Applicable Specifications table, Sheet, Plate and Strip rows - system: ASTM code: B124 note: forgings source: australwright-c65500 where: Applicable Specifications table, Bar, Forging and Forgings rows - system: ASTM code: B315 note: tube and pipe source: australwright-c65500 where: Applicable Specifications table, Tube and Pipe rows - system: ASTM code: B99 note: wire source: australwright-c65500 where: Applicable Specifications table, Wire row - system: Trade name code: Everdur source: australwright-c65500 where: Introduction paragraph, American trade name for wire and rod - system: Trade name code: Cusilman source: australwright-c65500 where: Introduction paragraph, Australian trade name for sheet, plate, circles and ingot tags: environments: [] stresses: [] applications: - structures - mechanisms properties: - benchmark: density label: Density, silicon bronze C65500 value: 8.53 unit: g/cm3 scope: material conditions: grade: C65500 temperature: 20 degC unit_in_source: 0.308 lb/in3 at 68 degF method: Value printed in the physical properties table of the Australwright datasheet status: ground source: australwright-c65500 where: Physical Properties table, row Density - benchmark: melting_point label: Solidus and liquidus, silicon bronze C65500 value: 971 value_high: 1027 bound: range unit: degC scope: material conditions: grade: C65500 unit_in_source: solidus 1780 degF; liquidus 1880 degF pressure: not stated method: Solidus (low) and liquidus (high) printed in the Australwright physical properties table status: ground note: The Wieland page prints a melting range of 970 to 1025 degC; the Australwright figures are used here. source: australwright-c65500 where: Physical Properties table, rows Melting Point (Liquidus) and Melting Point (Solidus) - benchmark: electrical_conductivity label: Electrical conductivity, silicon bronze C65500 value: 7 unit: '%IACS' scope: material conditions: grade: C65500 temperature: 68 degF (20 degC) method: Value printed in the Australwright physical properties table status: ground source: australwright-c65500 where: Physical Properties table, row Electrical Conductivity - benchmark: thermal_conductivity label: Thermal conductivity, silicon bronze C65500 value: 36.3 unit: W/(m.K) scope: material conditions: grade: C65500 temperature: 20 degC unit_in_source: 36.3 W/m.degK at 20 degC; 21.0 Btu.ft/(hr.ft2.degF) at 68 degF method: Printed as 36.3 W/m.degK at 20 degC; the unit is written here as W/(m.K), which is the same unit status: ground source: australwright-c65500 where: Physical Properties table, row Thermal Conductivity - benchmark: specific_heat label: Specific heat, silicon bronze C65500 value: 376.78 unit: J/(kg.K) scope: material conditions: grade: C65500 temperature: 293 K (20 degC) unit_in_source: 376.78 J/kg.degK at 293 degK method: Value printed in the Australwright physical properties table status: ground source: australwright-c65500 where: Physical Properties table, row Specific Heat - benchmark: cte label: Mean coefficient of thermal expansion, 20 to 300 degC value: 18 unit: um/(m.degC) scope: material conditions: grade: C65500 range: 20 to 300 degC unit_in_source: 18.0 x 10-6 per degC at 20 degC (20-300 degC) method: Printed as 18.0 x 10-6 per degC; 10-6 per degC is the same unit as um/(m.degC) status: ground source: australwright-c65500 where: Physical Properties table, row Mean Coefficient of Expansion, metric column - benchmark: elastic_modulus label: Modulus of elasticity in tension, silicon bronze C65500 value: 103400 unit: MPa scope: material conditions: grade: C65500 mode: tension unit_in_source: 15,000 ksi method: Value printed in the Australwright physical properties table status: ground source: australwright-c65500 where: Physical Properties table, row Modulus of Elasticity (Tension), metric column - benchmark: shear_modulus label: Modulus of rigidity in torsion, silicon bronze C65500 value: 38610 unit: MPa scope: material conditions: grade: C65500 mode: torsion unit_in_source: 5,600 ksi method: Value printed in the Australwright physical properties table status: ground source: australwright-c65500 where: Physical Properties table, row Modulus of Rigidity (Torsion), metric column - benchmark: electrical_resistivity label: Electrical resistivity, silicon bronze C65500 value: 24.6 unit: microohm-cm scope: material conditions: grade: C65500 temperature: 20 degC unit_in_source: 24.6 microhm-cm at 20 degC method: Value printed in the Australwright physical properties table status: ground source: australwright-c65500 where: Physical Properties table, row Electrical Resistivity, metric column - benchmark: ultimate_tensile_strength label: Tensile strength, H02 flat product 1 mm value: 538 unit: MPa scope: material conditions: temper: H02 form: flat product section: 1 mm temperature: 20 degC method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row H02 section 1 mm, Tensile Strength column - benchmark: yield_strength label: Yield strength at 0.5 % extension, H02 flat product 1 mm value: 310 unit: MPa scope: material conditions: temper: H02 form: flat product section: 1 mm temperature: 20 degC basis: 0.5 % extension under load method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row H02 section 1 mm, Yield Strength column - benchmark: elongation label: Elongation, H02 flat product 1 mm value: 17 unit: '%' scope: material conditions: temper: H02 form: flat product section: 1 mm temperature: 20 degC method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row H02 section 1 mm, Elongation column - benchmark: ultimate_tensile_strength label: Tensile strength, H04 flat product 1 mm value: 648 unit: MPa scope: material conditions: temper: H04 form: flat product section: 1 mm temperature: 20 degC method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row H04 section 1 mm, Tensile Strength column - benchmark: yield_strength label: Yield strength at 0.5 % extension, H04 flat product 1 mm value: 400 unit: MPa scope: material conditions: temper: H04 form: flat product section: 1 mm temperature: 20 degC basis: 0.5 % extension under load method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row H04 section 1 mm, Yield Strength column - benchmark: ultimate_tensile_strength label: Tensile strength, H08 flat product 1 mm value: 758 unit: MPa scope: material conditions: temper: H08 form: flat product section: 1 mm temperature: 20 degC method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row H08 section 1 mm, Tensile Strength column - benchmark: yield_strength label: Yield strength at 0.5 % extension, H08 flat product 1 mm value: 427 unit: MPa scope: material conditions: temper: H08 form: flat product section: 1 mm temperature: 20 degC basis: 0.5 % extension under load method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row H08 section 1 mm, Yield Strength column - benchmark: ultimate_tensile_strength label: Tensile strength, OS070 flat product 1 mm (soft temper) value: 386 unit: MPa scope: material conditions: temper: OS070 form: flat product section: 1 mm temperature: 20 degC method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row OS070 section 1 mm, Tensile Strength column - benchmark: yield_strength label: Yield strength at 0.5 % extension, OS070 flat product 1 mm (soft temper) value: 145 unit: MPa scope: material conditions: temper: OS070 form: flat product section: 1 mm temperature: 20 degC basis: 0.5 % extension under load method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row OS070 section 1 mm, Yield Strength column - benchmark: elongation label: Elongation, OS070 flat product 1 mm (soft temper) value: 63 unit: '%' scope: material conditions: temper: OS070 form: flat product section: 1 mm temperature: 20 degC method: Room-temperature value printed in the Australwright mechanical properties table status: ground source: australwright-c65500 where: Mechanical Properties table, Flat Products, row OS070 section 1 mm, Elongation column - benchmark: ultimate_tensile_strength label: Tensile strength range, H04 hard-drawn rod up to 6.35 mm value: 615 value_high: 689 bound: range unit: MPa scope: material conditions: temper: H04 form: rod and bar, hard drawn section: up to 0.25 in (6.35 mm) method: Range printed in the Wieland mechanical properties table; value is the low end and value_high the high end status: ground source: wieland-c65500 where: Mechanical Properties table, Rod and Bar, H04, first size row, UTS N/mm2 column - benchmark: yield_strength label: Yield strength range at 0.5 % extension, H04 hard-drawn rod up to 6.35 mm value: 380 value_high: 420 bound: range unit: MPa scope: material conditions: temper: H04 form: rod and bar, hard drawn section: up to 0.25 in (6.35 mm) basis: 0.5 % extension method: Range printed in the Wieland mechanical properties table; value is the low end and value_high the high end status: ground source: wieland-c65500 where: Mechanical Properties table, Rod and Bar, H04, first size row, 0.5 % Yield column - benchmark: elongation label: Elongation range, H04 hard-drawn rod up to 6.35 mm value: 8 value_high: 19 bound: range unit: '%' scope: material conditions: temper: H04 form: rod and bar, hard drawn section: up to 0.25 in (6.35 mm) method: Range printed in the Wieland mechanical properties table; value is the low end and value_high the high end status: ground source: wieland-c65500 where: Mechanical Properties table, Rod and Bar, H04, first size row, Elong column checked_values: 22 corrosion: - environment: Industrial, marine and rural atmospheres; many natural waters; stagnant and low-velocity sea water headline: Listed by the datasheet as suitable service; no corrosion rate printed. effect: The Australwright datasheet lists these as service experience with the alloy. It prints no rate in mm per year or mpy for any of them. rating: low conditions: basis: qualitative service list, no test data exposure: not stated source: australwright-c65500 where: Corrosion properties section, Service experience list - environment: Seawater and other polluted water systems headline: Excellent corrosion properties in sea water, per Wieland; no rate printed. effect: Wieland describes the alloy as single-phase and high in copper with excellent corrosion properties in seawater and polluted water, and with anti-biofouling behaviour in seawater. No numeric corrosion rate is printed on that page. rating: low conditions: basis: qualitative product description exposure: not stated source: wieland-c65500 where: Details section, paragraphs on corrosion and anti-biofouling - environment: Non-oxidising acids, alkalis and salts, for example sulphuric acid cold up to 90 % and caustic soda up to 40 % headline: Datasheet lists these as suitable, provided no oxidising agents are present. effect: Australwright lists sulphuric acid cold up to 90 %, hot up to 30 % in the absence of oxidising agents, caustic soda up to 40 % cold or hot, and a range of organic chemicals and salts as suitable. rating: low conditions: basis: qualitative service list, no test data exposure: concentrations as printed in the datasheet source: australwright-c65500 where: Corrosion properties section, Service experience list (Acids and Alkalies rows) - environment: Ammonia, hot ferric chloride, hydrogen sulphide, nitric acid and mercury salts headline: Datasheet says not to use the alloy in these media. effect: The datasheet lists alkaline sulphides, aqueous ammonia, hot ferric chloride, hydrogen sulphide, mercury and its salts, and nitric acid among the media it should not be used in. rating: moderate conditions: basis: supplier advice, no test data exposure: not stated source: australwright-c65500 where: Corrosion properties section, Importantly silicon bronze should not be used for the following list - environment: Steam or water above 100 degC for long periods; service above 150 degC headline: Corrosive attack and creep limit long-term hot service. effect: The datasheet says contact with steam or water above 100 degC for long periods may cause corrosive attack, especially under stress or cycling. It also says the alloy creeps over long periods above 150 degC and recommends against service above that temperature. rating: moderate conditions: basis: supplier advice, no test data exposure: long-term; duration not stated source: australwright-c65500 where: Corrosion properties section, Service at elevated temperature risks: hazards: - text: 'Supplier safety data sheet for a silicon bronze alloy family (product codes C64200, C65100, C65500, C66100 and others): signal word Danger; combustible dust; reproductive toxicity category 1A; specific target organ toxicity from repeated exposure category 1; hazardous to the aquatic environment, acute category 1 and long-term category 2. The sheet covers a family of grades, not C65500 alone.' ghs: [] source: sam-sds where: Section 2, Hazard(s) identification, signal word and hazard statements - text: Dust and fumes form when the alloy is heated, cut, ground or welded; heating above the melting point releases metallic oxides that can cause metal fume fever, with shivering, fever and muscular pain. ghs: [] source: sam-sds where: Section 4 (Most important symptoms) and Section 11 (Inhalation) - text: Contact with strong acids releases flammable hydrogen gas. In a fire the sheet notes toxic vapours and fumes of lead and lead compounds, because the family includes leaded grades. ghs: [] source: sam-sds where: Section 5 (Specific hazards arising from the chemical) and Section 10 (Incompatible materials) - text: 'PubChem GHS for manganese metal (a component of the alloy): flammable solid in 11.6 % of notifications and serious eye irritation in 14.8 %; these describe the pure metal, not the solid alloy.' ghs: - H228 - H319 source: pubchem-mn where: Safety and Hazards, GHS Classification, hazard statements failure_risks: - mode: Creep and loss of design strength in hot service trigger: Service above 150 degC, or contact with steam above 100 degC for long periods consequence: Creep over long service; the datasheet says design stresses based on creep data are comparatively low at temperature. severity: moderate source: australwright-c65500 where: Corrosion properties section, Service at elevated temperature - mode: Attack in named process chemicals trigger: Ammonia, hot ferric chloride, hydrogen sulphide, nitric acid or mercury salts consequence: The datasheet advises against these media; attack is not quantified in the source. severity: moderate source: australwright-c65500 where: Corrosion properties section, list of media the alloy should not be used in - mode: Hydrogen release on contact with acid trigger: Contact with strong acids consequence: Flammable hydrogen gas is released, creating a fire and explosion hazard in closed spaces. severity: moderate source: sam-sds where: Section 5, Specific hazards arising from the chemical handling: - text: Do not breathe dust or fume; control dust and fume when cutting, grinding or welding, and avoid dust build-up because fine dust can form an explosive mixture with air. source: sam-sds where: Section 2 (precautionary statements) and Section 5 (explosion hazard) - text: Keep service below 150 degC, and keep steam or hot water below 100 degC for long periods unless the creep and corrosion behaviour has been checked. source: australwright-c65500 where: Corrosion properties section, Service at elevated temperature - text: Keep away from strong oxidising agents and acids; both are listed as incompatible in the safety data sheet. source: sam-sds where: Section 10, Incompatible materials documents: - title: Austral Wright Metals, Silicon Bronze C65500 product page (composition, physical and mechanical tables, applications, corrosion) type: datasheet url: https://www.australwright.com.au/technical-data/alloys/copper-brass/copper-alloys-c65500-silicon-bronze/ year: 2026 - title: Wieland Diversified, Bronze CDA 65500 technical page (international standards, mechanical and physical properties) type: datasheet url: https://www.wieland-diversified.com/bronze-overview/bronze-cda-65500/ year: 2026 - title: Stanford Advanced Materials, Silicon Bronze Alloy safety data sheet, SDS 11 type: sds url: https://www.samaterials.com/tds/sc/1783992984-CU8125.pdf year: 2018 - title: 'PubChem: Manganese (CID 23930), GHS classification' type: database url: https://pubchem.ncbi.nlm.nih.gov/compound/23930 year: 2026 - title: 'Wikipedia: Bronze (silicon bronze composition)' type: database url: https://en.wikipedia.org/wiki/Bronze year: 2026 - title: 'USGS Mineral Commodity Summaries 2026: Copper' type: report url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf year: 2026 - title: 'USGS Mineral Commodity Summaries 2026: Silicon' type: report url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silicon.pdf year: 2026 - title: 'USGS Mineral Commodity Summaries 2026: Manganese' type: report url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-manganese.pdf year: 2026 gaps: - No seawater or marine corrosion rate in mm per year or mpy was printed on any page read. Wieland and Australwright both describe the sea-water resistance qualitatively only. - 'Nominal composition differs between pages: the Australwright text gives 96 % copper, 3 % silicon and 1 % manganese, its table gives nominal copper 97.0, manganese 0.9 and silicon 3.0, and Wieland gives 95 % copper, 4 % silicon and 1 % manganese. Only the printed min and max ranges are used in identity.' - 'Melting ranges differ slightly: Australwright prints solidus 971 degC and liquidus 1027 degC, Wieland prints 970 to 1025 degC. The Australwright figures are used.' - Hardness (Rockwell B, Rockwell F, Vickers) and fatigue strength are printed on the Australwright table, but the extracted column layout does not show which value belongs to which column, so none are entered. - The Wieland modulus values are printed as 15 ksi and 103 N/mm2, with a printing error on the rigidity figure; the Australwright metric values are used instead. - Only the H04 hard-drawn rod ranges come from Wieland, and they apply to rod and bar up to 6.35 mm; no flat-product or wire values from Wieland are used. - The safety data sheet covers a family of silicon bronze grades, and its lead range of 0 to 0.8 % is wider than the C65500 lead maximum of 0.05 % printed by Australwright. The hazard entries are therefore the family's, not C65500 alone. - No C65500-specific SDS was found. The PubChem GHS entries describe manganese metal, not the alloy. - The trade name High-Silicon Bronze A was seen in search results but was not printed on any fetched page, so it is not entered. - The US 2025 list entry for silicon and copper is from the USGS chapters. Manganese is not stated as critical in its USGS chapter, and no EU critical raw materials list was checked for silicon, manganese or copper. - Manganese and silicon shares are calculated from the 2025 estimates in the USGS tables (silicon metal total 4,600 t; manganese total 20,000 kt); they are not printed as percentages. - No vacuum, outgassing, radiation, atomic oxygen or thermal-cycling data for C65500 was found in the sources read. - The Wieland page gives an ASTM B98 and B124 specification set, but its UNS and specification table is not fully legible in the extracted text, so only codes printed in the Australwright table are entered as ASTM designations. uses: - application: structures device: Welded tanks, pressure vessels and process vessels example: Australwright lists welded tanks, process vessels, calorifiers and domestic hot water cylinders as uses of silicon bronze, and says it is one of the easiest copper alloys to weld. source: australwright-c65500 where: Silicon Bronze Applications section and Welding properties section - application: mechanisms device: Bushings, bearing plates and piston rings example: The Australwright industrial application list names bushings, bearing plates, piston rings and heat exchanger tubes. source: australwright-c65500 where: Silicon Bronze Applications table, Industrial row - application: mechanisms device: Fasteners, hinges and marine hardware example: Wieland says silicon bronze is used in pump and valve components, fasteners, piston rings and marine hardware. source: wieland-c65500 where: Details section, first paragraph supply: - subject: Copper (remainder of the alloy) producers: - country: Chile share_percent: 23 year: 2025 - country: Congo (Kinshasa) share_percent: 13.9 year: 2025 - country: Peru share_percent: 11.7 year: 2025 - country: China share_percent: 7.8 year: 2025 - country: Russia share_percent: 5.7 year: 2025 critical_lists: - list: U.S. Final 2025 List of Critical Minerals (copper added, 90 FR 50494) listed: true recycling: 'USGS, U.S. section: old scrap converted to refined metal, alloys and other forms provided an estimated 160,000 tons of copper in 2025, and scrap supplied about 30 % of U.S. copper supply.' substitutes: - 'USGS: aluminum substitutes for copper in automobile radiators, electrical equipment and power cable; optical fiber substitutes in telecommunications.' source: usgs-mcs2026-copper where: World Mine and Refinery Production and Reserves table, mine production 2025e in thousand tons of copper content (world total 23,000; Chile 5,300; Congo (Kinshasa) 3,200; Peru 2,700; China 1,800; Russia 1,300); shares calculated from those values; Recycling; Substitutes; critical minerals text - subject: Silicon (ferrosilicon and silicon metal feed) producers: - country: China share_percent: 87 year: 2025 - country: Brazil share_percent: 3.9 year: 2025 - country: Norway share_percent: 2.8 year: 2025 - country: France share_percent: 1.5 year: 2025 - country: Russia share_percent: 0.8 year: 2025 critical_lists: - list: U.S. Final 2025 List of Critical Minerals (silicon added, 90 FR 50494) listed: true recycling: 'USGS: recycling of silicon is insignificant.' substitutes: - 'USGS: aluminum, silicon carbide and silicomanganese can be substituted for ferrosilicon in some applications.' source: usgs-mcs2026-silicon where: World Production table, silicon metal, 2025 column (China 4,000; Brazil 180; Norway 130; France 68; Russia 35; world total read as 4,600 thousand t of silicon content); shares calculated from those values; Recycling; Substitutes; critical minerals text - subject: Manganese producers: - country: South Africa share_percent: 38 year: 2025 - country: Gabon share_percent: 25 year: 2025 - country: Ghana share_percent: 10 year: 2025 - country: Australia share_percent: 8 year: 2025 critical_lists: [] recycling: 'USGS: manganese was recycled incidentally with ferrous and nonferrous scrap; scrap recovery specifically for manganese was negligible.' substitutes: - 'USGS: manganese has no satisfactory substitute in its major applications.' source: usgs-mcs2026-manganese where: World Mine Production and Reserves table, 2025e in thousand metric tons of manganese content (world total 20,000; South Africa 7,600; Gabon 5,000; Ghana 2,000; Australia 1,600); shares calculated from those values; Recycling; Substitutes. The chapter does not state a critical-minerals status, so none is entered. license: CC-BY-4.0 updated: '2026-10-26' review: status: draft method: assistant checked_values: 22 unreachable: 0 caveats: 2 note: Read by an AI assistant on 2026-10-26 from the Australwright and Wieland datasheets, the Wikipedia Bronze article, the Stanford Advanced Materials safety data sheet, PubChem and USGS Mineral Commodity Summaries 2026. Values are checked against the printed pages by verify-values. sources: australwright-c65500: title: Austral Wright Metals, Silicon Bronze C65500 product page url: https://www.australwright.com.au/technical-data/alloys/copper-brass/copper-alloys-c65500-silicon-bronze/ kind: datasheet license: Manufacturer technical page (cited, not reproduced) wieland-c65500: title: Wieland Diversified, Bronze CDA 65500 (silicon bronze C65500) technical page url: https://www.wieland-diversified.com/bronze-overview/bronze-cda-65500/ kind: datasheet license: Manufacturer technical page (cited, not reproduced) wikipedia-bronze: title: 'Wikipedia: Bronze (redirected from Silicon bronze)' url: https://en.wikipedia.org/wiki/Bronze kind: web license: CC BY-SA 4.0 (cited, not reproduced) sam-sds: title: Stanford Advanced Materials, Silicon Bronze Alloy safety data sheet, SDS 11 (revision 29 October 2018) url: https://www.samaterials.com/tds/sc/1783992984-CU8125.pdf kind: datasheet license: Manufacturer safety data sheet (cited, not reproduced) pubchem-mn: title: 'PubChem: Manganese (CID 23930), GHS classification' url: https://pubchem.ncbi.nlm.nih.gov/compound/23930 kind: database license: PubChem public database (cited, not reproduced) usgs-mcs2026-copper: title: Mineral Commodity Summaries 2026, Copper url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf year: 2026 kind: report license: public domain (USGS) usgs-mcs2026-silicon: title: Mineral Commodity Summaries 2026, Silicon url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silicon.pdf year: 2026 kind: report license: public domain (USGS) usgs-mcs2026-manganese: title: Mineral Commodity Summaries 2026, Manganese url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-manganese.pdf year: 2026 kind: report license: public domain (USGS) story: recipe: line: C65500 is a copper-silicon-manganese alloy. Copper is the matrix, silicon gives strength and acts as a deoxidiser in the melt, and manganese adds strength and forms manganese silicides when the alloy is age hardened. It is wrought into rod, bar, sheet, plate, tube, forgings and wire, and it can be cold worked before or after the age hardening (Wieland). parts: - name: Copper symbol: Cu share: remainder (nominal 97.0 wt % in the Australwright table) role: The matrix. The alloy is a single-phase copper-rich alpha alloy, which keeps the ductility and conductivity of copper (Wieland, Australwright). - name: Silicon symbol: Si share: 2.8 to 3.8 wt % role: The main alloying element. It raises strength, lowers electrical conductivity to about that of steel, and is a deoxidant in the melt (Australwright). - name: Manganese symbol: Mn share: 0.50 to 1.3 wt % role: Raises tensile, yield and fatigue strength, and forms manganese silicides on age hardening (Australwright, Wieland). risk_groups: - title: For people level: 1 verdict: Dust and fume are the main hazard lead: The supplier safety data sheet for the silicon bronze family carries a Danger signal word, and the main exposure route is dust and fume from heating, cutting, grinding or welding. points: - label: Dust and fume line: Dust and fume form on heating, cutting or welding. Heating above the melting point releases metallic oxides that can cause metal fume fever. - label: Reproductive and organ effects line: The family sheet classes it as reproductive toxicity category 1A and as a specific target organ toxicant after repeated exposure, category 1. - label: Manganese line: Long-term breathing of manganese dust or fume can cause manganism, a nervous system disease like Parkinson's disease, according to the sheet. - title: For the part level: 1 verdict: Acid contact makes hydrogen lead: The alloy is stable in many media, but strong acids release flammable hydrogen, and fine dust can form an explosive mixture. points: - label: Acids line: Contact with strong acids releases flammable hydrogen gas, according to the safety data sheet. - label: Dust explosion line: Fine dust in air with an ignition source is a potential dust explosion hazard, and the sheet asks for dust build-up to be prevented. - title: For the environment level: 1 verdict: Toxic to aquatic life lead: The safety data sheet classes the alloy family as hazardous to the aquatic environment. points: - label: Aquatic line: The family sheet gives acute hazard category 1 and long-term hazard category 2 for the aquatic environment. why: Silicon bronze C65500 combines the strength and formability of mild steel with the corrosion resistance of copper, according to the Australwright datasheet. The datasheet gives a tensile strength of 538 MPa and a yield strength of 310 MPa for the H02 flat product, and it names welded vessels, fasteners and bushings among its applications. uses: - where: Welded tanks and pressure vessels line: Australwright lists welded tanks, process vessels and high-strength, corrosion-resistant welded vessels among its uses, and says the alloy is one of the easiest copper alloys to weld. - where: Bushings, bearing plates and piston rings line: The Australwright industrial list names bushings, bearing plates, piston rings and heat exchanger tubes among its applications. - where: Fasteners and marine hardware line: Australwright lists hinges, bolts, nails, screws, rivets, nuts and cotter pins among fasteners, and Wieland says silicon bronze is used in pump and valve parts, fasteners, piston rings and marine hardware. can_do: - label: Carry load in hard temper value: 648 MPa tensile (H04) benchmark: ultimate_tensile_strength line: The H04 flat product, 1 mm, has a tensile strength of 648 MPa and a yield strength of 400 MPa at 20 degC. - label: Conduct heat value: 36.3 W/(m.K) benchmark: thermal_conductivity line: The Australwright datasheet gives a thermal conductivity of 36.3 W/m.degK at 20 degC. - label: Take the density value: 8.53 g/cm3 benchmark: density line: The Australwright datasheet gives a density of 8.53 g/cm3 at 20 degC. - label: Melt value: 971 to 1027 degC benchmark: melting_point line: The solidus is 971 degC and the liquidus is 1027 degC in the Australwright physical properties table. compare: Silicon bronze C65500 is a single-phase copper alloy with silicon and manganese in the strength range above mild copper. Silicon lowers its electrical conductivity to 7 %IACS, which the Australwright datasheet compares with steel, so it is a poor choice for current-carrying parts. The thermal expansion and density figures in the rows below are its own printed values; compare them with the other copper alloys in this set rather than with numbers from this file. compare_rows: - label: Density benchmark: density - label: Electrical conductivity benchmark: electrical_conductivity - label: Thermal expansion benchmark: cte handling: - 'Specify the temper, since the strength depends strongly on it: H04 hard and H08 spring tempers are much stronger than the soft OS070 temper.' - Keep service below 150 degC, and keep steam or hot water below 100 degC for long periods unless creep and corrosion have been checked. - Control dust and fume when cutting, grinding or welding, and avoid dust build-up. good_for: - Welded vessels and tanks, where the datasheet calls the alloy easy to weld and corrosion resistant. - Fasteners, bushings and marine hardware in sea water and polluted water, per Wieland and Australwright. - Parts that need copper-like corrosion resistance with more strength than copper, such as hinges and piston rings. watch_out: - Electrical conductivity is only 7 %IACS, so do not use it for current-carrying parts. - The datasheet advises against service above 150 degC and against steam above 100 degC for long periods. - Do not use it in ammonia, hot ferric chloride, hydrogen sulphide, nitric acid or mercury salts, per the datasheet. - No seawater corrosion rate in mm per year was found; the sea-water resistance is qualitative. verdict: Silicon bronze C65500 is a strong, weldable and corrosion-resistant copper alloy with 2.8 to 3.8 % silicon and 0.50 to 1.3 % manganese. Its strength depends on temper, and the H08 flat product reaches 758 MPa tensile strength. Its conductivity is low, its hot service limit is 150 degC, and its dust and fume need controlling in use. The profile has no numeric corrosion rate and no hardness or fatigue values.