Copper Alloy C16500
UNS C16500
C16500 is a wrought cadmium copper with a tin addition, part of the lightly alloyed copper family (C10000–C19999), giving higher strength and wear resistance than plain cadmium copper while holding 62 % IACS and 235 W/m·K.
Reference datasheet — C16500 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the H04 condition
C16500 tempers and conditions
C16500 is supplied in 5 conditions, soft to hard. H04 is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.050 mm grain size | Pick the annealed 0.050 mm grain-size temper for deep drawing, bending or further cold work: highest conductivity at 65% IACS and 35% elongation, but the lowest strength at 110 MPa yield. | 110 | 324 | 35 | 55 HB | 65 % IACS |
H04Default Full hard | Choose this most commonly stocked temper, cold worked about 37%, for wire, commutator segments and contacts balancing 430 MPa yield, wear resistance and 62% IACS; forming margin is limited. | 430 | 462 | 4 | 120 HB | 62 % IACS |
Extra hard | Use for conductive parts needing 469 MPa yield, above full hard, with only light forming after roughly 50% cold reduction; elongation falls to 3% and conductivity to 61% IACS. | 469 | 496 | 3 | 130 HB | 61 % IACS |
Spring hard | Pick the spring temper from about 60% cold reduction for conductive springs and contact blades requiring a high elastic limit at 496 MPa yield; 2% elongation leaves little forming margin. | 496 | 524 | 2 | 140 HB | 60 % IACS |
Extra spring hard | Choose the heavily cold worked extra-spring temper for the highest strength, 517 MPa yield, in thin-strip high-stress elastic contacts; at 1.5% elongation there is essentially no forming margin. | 517 | 545 | 1.5 | 147 HB | 59 % IACS |
What is C16500?
C16500 is a wrought cadmium copper with a tin addition, part of the lightly alloyed copper family (C10000–C19999), giving higher strength and wear resistance than plain cadmium copper while holding 62 % IACS and 235 W/m·K. It is drawn and rolled into trolley and contact wire, strip and spring stock that must resist arc erosion and sliding wear yet still carry current; the default condition gives 430 MPa yield, 462 MPa tensile and 120 HB (68 HRB). Limits are 4 % elongation in the hard tempers, a 200 °C maximum service temperature and mandatory controls on cadmium fume and dust; C18150 chromium-zirconium copper is the usual cadmium-free substitute. C16500 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,030°C (1,886 °F). C16500 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 462 MPa (67 ksi) — stronger than 84% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 117 GPa (17 Msi).
What is C16500 used for?
- electrical contacts
- trolley wire
- springs
Advantages
- High strength — 430 MPa (62.4 ksi), better than 84% of copper alloy grades
- High electrical conductivity — 62 % IACS, better than 82% of copper alloy grades
- Conducts heat well — 235 W/m·K (135.8 BTU/hr·ft·°F), better than 81% of copper alloy grades
Limitations
- Limited ductility — 4%, worse than 96% of copper alloy grades
- Difficult to machine — 22/100, worse than 94% of copper alloy grades
C16500 properties
Typical room-temperature values for C16500-H04; bars are the position among copper alloy grades.
Physical3
C16500 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,030°C (1,886 °F).
Mechanical12
C16500 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 462 MPa (67 ksi) — stronger than 84% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C16500 is rated for continuous service to 200°C (392 °F). It conducts heat at 235 W/m·K (135.8 BTU/hr·ft·°F), better than 81% of copper alloy grades. Thermal expansion is 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C16500 conducts electricity at 62 % IACS, better than 82% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 69% of copper alloy grades.
Sustainability4
Producing a kilogram of C16500 takes about 57 MJ of energy and emits 3.6 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 25%.
Manufacturability8
C16500's machinability is poor (22/100, worse than 94% of copper alloy grades); weldability fair (45/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C16500 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C16500
Is C16500 easy to machine?
Machinability is roughly 20 % of free-cutting brass and the alloy smears badly on the tool, so use sharp tooling with large positive rake, high cutting speed and generous coolant. Do not cut dry — cadmium-bearing dust must be avoided.
Can C16500 be welded?
Resistance welding and brazing are the practical joining routes. In fusion welding cadmium vaporises and forms toxic fume, so forced local exhaust is mandatory and brazing or soldering should be given preference.
Can C16500 be formed, bent or molded?
Cold formability is good in the annealed OS050 temper, which supports deep drawing and tight bends. In H04 and harder tempers keep the bend radius at or above 2t, and use an intermediate anneal at about 400–500 °C before heavy forming.
C16500 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 |
|---|---|---|
| Cdmain element for strength and softening resistance | 0.5 – 0.7 | 0.6 |
| Snfurther increases strength and wear resistance | 0.5 – 0.7 | 0.6 |
| Feimpurity limit | ≤ 0.02 | |
| Pdeoxidizer | 0 – 0.01 | 0.01 |
| Cubalance, Cu+Ag ≥ 98.6% | balance |
What surface finishes work on C16500?
Not anodisable. Silver, tin or nickel plating is used to control contact resistance; the alloy polishes well and forms a protective natural patina outdoors.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
How much does C16500 cost?
C16500 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C16500 — frequently asked
What is C16500 used for?
C16500 is typically used for electrical contacts, trolley wire and springs. In short: wear-resistant contact copper; 62 % IACS at 430 MPa; cadmium fume control required.
What is the yield strength of C16500?
C16500 has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 462 MPa (67 ksi) — stronger than 84% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C16500 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 94% of copper alloy grades). Machinability is roughly 20 % of free-cutting brass and the alloy smears badly on the tool, so use sharp tooling with large positive rake, high cutting speed and generous coolant. Do not cut dry — cadmium-bearing dust must be avoided.
Can C16500 be welded?
With care — weldability is rated fair (45/100). Resistance welding and brazing are the practical joining routes. In fusion welding cadmium vaporises and forms toxic fume, so forced local exhaust is mandatory and brazing or soldering should be given preference.
What surface finishes work on C16500?
Not anodisable. Silver, tin or nickel plating is used to control contact resistance; the alloy polishes well and forms a protective natural patina outdoors.
Can C16500 be formed, bent or molded?
Cold formability is good in the annealed OS050 temper, which supports deep drawing and tight bends. In H04 and harder tempers keep the bend radius at or above 2t, and use an intermediate anneal at about 400–500 °C before heavy forming.
What is the maximum service temperature of C16500?
C16500 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 C16500-H04 and C16500-OS050?
H04 is the default condition — choose this most commonly stocked temper, cold worked about 37%, for wire, commutator segments and contacts balancing 430 MPa yield, wear resistance and 62% IACS; forming margin is limited. OS050: pick the annealed 0.050 mm grain-size temper for deep drawing, bending or further cold work: highest conductivity at 65% IACS and 35% elongation, but the lowest strength at 110 MPa yield. Yield strength is 430 MPa in H04 versus 110 MPa in OS050.
How much does C16500 cost?
C16500 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- CDA Alloy C16500 (cadmium-tin copper) datasheet — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASTM B105 — Hard-Drawn Copper Alloy Wires for Electric Conductors — ASTM (2020)
- ASTM B624 / UNS designation system for copper alloys — ASTM / CDA (2019)
- ASM Handbook Vol.13 — Corrosion of copper and copper alloys — ASM International (2005)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.