Copper Alloy C43500-OS035
Temper
UNS C43500
OS035 = annealed to 0.035 mm grain size
Softest commercial temper — pick for deep drawing, tube bending and severe forming of bellows/Bourdon blanks.
Values for the OS035 condition
Other C43500 tempers and conditions
C43500 is listed in 8 conditions; see the grade overview at C43500.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OS035This page Annealed to 0.035 mm grain size | Softest commercial temper — pick for deep drawing, tube bending and severe forming of bellows/Bourdon blanks. | 110 | 315 | 50 | 55 HB | 28 % IACS |
OS025Default Annealed to 0.025 mm grain size | Standard stocked soft temper: fine grain gives a smooth drawn surface (orange-peel free) with still-excellent formability. | 125 | 330 | 46 | 60 HB | 28 % IACS |
Quarter hard | Light cold work for parts needing extra stiffness while retaining moderate bend formability. | 275 | 380 | 25 | 95 HB | 27.5 % IACS |
Hard drawn | Standard as-drawn tube temper for Bourdon tubes, gauge and instrument tubing needing elastic response with some bendability. | 310 | 415 | 20 | 115 HB | — |
Half hard | Best strength/formability compromise for springy clips, ferrules and gauge parts that still need 90° bends. | 345 | 420 | 13 | 120 HB | — |
Full hard | Full-hard strip for flat springs, contacts and stamped parts requiring high yield strength and only gentle forming. | 450 | 505 | 5 | 145 HB | — |
Extra hard | Choose when higher spring rate than H04 is needed and forming is limited to flat blanking. | 505 | 560 | 4 | 160 HB | 27 % IACS |
Spring hard | Maximum-strength strip temper for flat springs and diaphragms; essentially no cold forming capability. | 540 | 605 | 3 | 172 HB | 27 % IACS |
What is C43500-OS035?
C43500-OS035 is C43500 in the OS035 temper — softest commercial temper — pick for deep drawing, tube bending and severe forming of bellows/Bourdon blanks. C43500-OS035 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 315 MPa (45.7 ksi) — weaker than 82% of copper alloy grades. Elongation at break is 50% and the elastic modulus is 110 GPa (16 Msi). C43500-OS035 has a density of 8.53 g/cm³ (0.308 lb/in³), lighter than 62% of copper alloy grades. It melts at 899°C (1,650 °F). OS025 is the default condition FabDigit quotes; OS035 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 50%, better than 97% of copper alloy grades
- Forms and bends easily — 92/100, better than 91% of copper alloy grades
Limitations
- Low strength — 110 MPa (16 ksi), worse than 82% of copper alloy grades
C43500-OS035 properties
Typical room-temperature values for C43500-OS035; 11 are specific to this condition. Other listed values are C43500 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C43500-OS035 has a density of 8.53 g/cm³ (0.308 lb/in³), lighter than 62% of copper alloy grades. It melts at 899°C (1,650 °F).
Mechanical12
C43500-OS035 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 315 MPa (45.7 ksi) — weaker than 82% of copper alloy grades. Elongation at break is 50% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
C43500-OS035 is rated for continuous service to 200°C (392 °F). It conducts heat at 116 W/m·K (67 BTU/hr·ft·°F), better than 64% of copper alloy grades. Thermal expansion is 20.3 µm/m·K (11.3 µin/in·°F).
Electrical3
C43500-OS035 conducts electricity at 28 % IACS, better than 69% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C43500-OS035 takes about 55 MJ of energy and emits 3.5 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 45%.
Manufacturability8
C43500-OS035's machinability is poor (28/100, worse than 78% of copper alloy grades); weldability fair (40/100); formability excellent (92/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C43500-OS035
Is C43500 easy to machine?
Machinability ~30 % of free-cutting brass — gummy, long chips; use sharp positive-rake tools, high speed, generous coolant and chip breakers.
Can C43500 be welded?
Solders and brazes excellently (best joining route); resistance and oxyacetylene welding fair, arc welding not recommended due to zinc fuming and porosity.
Can C43500 be formed, bent or molded?
Excellent cold formability in OS tempers — deep drawing, tube drawing and bending; stress-relieve at 250–300 °C after heavy forming to avoid season cracking.
What surface finishes work on C43500?
Not anodizable; polishes to a bright yellow-gold finish, accepts nickel/chrome/tin plating and clear lacquer, or can be chemically patinated.
C43500 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cucopper plus silver | 79 – 83 | 81 |
| Sn | 0.6 – 1.2 | 0.9 |
| Pb | ≤ 0.1 | — |
| Fe | ≤ 0.05 | — |
| Znremainder, nominally ~18 % | balance | — |
C43500-OS035 — frequently asked
What is C43500-OS035 used for?
C43500-OS035 is typically used for marine hardware, plumbing fittings and electrical hardware. In short: most formable tin brass; higher tin for corrosion resistance; deep-draw and tube grade.
What is the yield strength of C43500-OS035?
C43500-OS035 has a typical yield strength of 110 MPa (16 ksi) and a tensile strength of 315 MPa (45.7 ksi) — weaker than 82% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C43500-OS035 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% of copper alloy grades). Machinability ~30 % of free-cutting brass — gummy, long chips; use sharp positive-rake tools, high speed, generous coolant and chip breakers.
Can C43500-OS035 be welded?
With care — weldability is rated fair (40/100). Solders and brazes excellently (best joining route); resistance and oxyacetylene welding fair, arc welding not recommended due to zinc fuming and porosity.
What surface finishes work on C43500-OS035?
Not anodizable; polishes to a bright yellow-gold finish, accepts nickel/chrome/tin plating and clear lacquer, or can be chemically patinated.
Can C43500-OS035 be formed, bent or molded?
Excellent cold formability in OS tempers — deep drawing, tube drawing and bending; stress-relieve at 250–300 °C after heavy forming to avoid season cracking.
What is the maximum service temperature of C43500-OS035?
C43500-OS035 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C43500-OS025 and C43500-H08?
OS025 is the default condition — standard stocked soft temper: fine grain gives a smooth drawn surface (orange-peel free) with still-excellent formability. H08: maximum-strength strip temper for flat springs and diaphragms; essentially no cold forming capability. Yield strength is 125 MPa in OS025 versus 540 MPa in H08.
Sources
- ASTM B135 / B587 — Seamless Brass Tube and Welded Brass Tube — ASTM International (2019)
- ASTM B36/B36M — Brass Plate, Sheet, Strip and Rolled Bar — ASTM International (2018)
- CDA Alloy Database, C43500 tin brass — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- GB/T 26303 / GB/T 1527 (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.