Copper Alloy C15500-H08
Supply condition
UNS C15500
H08 = spring hard
Choose for flat springs and press contacts where elastic limit matters more than bendability.
Values for the H08 condition
Other C15500 tempers and conditions
C15500 is listed in 8 conditions; see the grade overview at C15500.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Light annealed | Softest supply condition — pick it for deep drawing, severe bending or when maximum conductivity and formability matter. | 80 | 235 | 42 | 45 HB | 93 % IACS |
Quarter hard | Light temper for parts that still need moderate bending but more stiffness than soft strip. | 205 | 270 | 25 | 70 HB | 92 % IACS |
Half hard | Best all-round strip temper: usable bend radii with roughly double the annealed yield strength. | 270 | 310 | 14 | 88 HB | 92 % IACS |
H04Default Full hard | Standard stocked temper for lead frames, commutator segments and contacts that must survive solder/braze heat with strength retained. | 310 | 345 | 6 | 100 HB | 92 % IACS |
H08This page Spring hard | Choose for flat springs and press contacts where elastic limit matters more than bendability. | 345 | 380 | 4 | 108 HB | 91 % IACS |
Extra spring hard | Higher cold-work level for thin contact springs needing extra elastic deflection. | 365 | 400 | 3 | 112 HB | 91 % IACS |
Strain hardened, quarter hard | Very heavily rolled strip for high-force miniature springs; bends only with the grain and generous radii. | 380 | 415 | 2.5 | 116 HB | 91 % IACS |
Strain hardened, half hard | Maximum strength temper of the C15500 strip range — flat parts, minimal forming, highest spring rate. | 400 | 430 | 2 | 120 HB | 90 % IACS |
What is C15500-H08?
C15500-H08 is C15500 supplied in the H08 condition — choose for flat springs and press contacts where elastic limit matters more than bendability. C15500-H08 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 380 MPa (55.1 ksi) — stronger than 73% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 117 GPa (17 Msi). C15500-H08 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F). H04 is the default condition FabDigit quotes; H08 is available on request or by drawing note.
Advantages
- High electrical conductivity — 91 % IACS, better than 88% of copper alloy grades
- Conducts heat well — 342 W/m·K (197.6 BTU/hr·ft·°F), better than 86% of copper alloy grades
Limitations
- Limited ductility — 4%, worse than 96% of copper alloy grades
- Difficult to machine — 24/100, worse than 91% of copper alloy grades
C15500-H08 properties
Typical room-temperature values for C15500-H08; 12 are specific to this condition. Other listed values are C15500 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C15500-H08 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,065°C (1,949 °F).
Mechanical12
C15500-H08 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 380 MPa (55.1 ksi) — stronger than 73% of copper alloy grades. Elongation at break is 4% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C15500-H08 is rated for continuous service to 250°C (482 °F). It conducts heat at 342 W/m·K (197.6 BTU/hr·ft·°F), better than 86% of copper alloy grades. Thermal expansion is 17.6 µm/m·K (9.78 µin/in·°F).
Electrical3
C15500-H08 conducts electricity at 91 % IACS, better than 88% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 69% of copper alloy grades.
Sustainability4
Producing a kilogram of C15500-H08 takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 30%.
Manufacturability8
C15500-H08's machinability is poor (24/100, worse than 91% of copper alloy grades); weldability good (55/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C15500-H08
Is C15500 easy to machine?
Gummy like pure copper (≈20 % of AISI 1212); use sharp positive-rake tools, high speed, low feed and flood coolant, or specify H04+ temper to reduce built-up edge.
Can C15500 be welded?
Excellent for soldering and brazing; GTAW/resistance welding are workable but the very high thermal conductivity demands preheat and high heat input — welding destroys the cold-worked strength locally.
Can C15500 be formed, bent or molded?
Anneals softly and cold-works readily; O50/H01 for deep draws and tight bends, H04 and above only for gentle bends with the grain.
What surface finishes work on C15500?
Not anodisable; tin, silver or nickel plate for solderability and tarnish resistance, or apply benzotriazole/lacquer to keep bright copper.
C15500 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 |
|---|---|---|
| Ag8–25 troy oz/ton silver addition; raises softening temperature | 0.03 – 0.1 | 0.06 |
| Pdeoxidiser | 0.04 – 0.08 | 0.06 |
| Mg | 0.08 – 0.13 | 0.1 |
| CuCu + Ag ≥ 99.75 % min | balance | — |
C15500-H08 — frequently asked
What is C15500-H08 used for?
C15500-H08 is typically used for commutator bars, motor windings and lead frames requiring soldering resistance. In short: anneal-resistant high-conductivity copper; holds temper through soldering; 92% IACS, 250 °C service.
What is the yield strength of C15500-H08?
C15500-H08 has a typical yield strength of 345 MPa (50 ksi) and a tensile strength of 380 MPa (55.1 ksi) — stronger than 73% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C15500-H08 easy to machine?
Not especially — machinability is rated poor (24/100, worse than 91% of copper alloy grades). Gummy like pure copper (≈20 % of AISI 1212); use sharp positive-rake tools, high speed, low feed and flood coolant, or specify H04+ temper to reduce built-up edge.
Can C15500-H08 be welded?
Yes — weldability is rated good (55/100). Excellent for soldering and brazing; GTAW/resistance welding are workable but the very high thermal conductivity demands preheat and high heat input — welding destroys the cold-worked strength locally.
What surface finishes work on C15500-H08?
Not anodisable; tin, silver or nickel plate for solderability and tarnish resistance, or apply benzotriazole/lacquer to keep bright copper.
Can C15500-H08 be formed, bent or molded?
Anneals softly and cold-works readily; O50/H01 for deep draws and tight bends, H04 and above only for gentle bends with the grain.
What is the maximum service temperature of C15500-H08?
C15500-H08 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C15500-H04 and C15500-O50?
H04 is the default condition — standard stocked temper for lead frames, commutator segments and contacts that must survive solder/braze heat with strength retained. O50: softest supply condition — pick it for deep drawing, severe bending or when maximum conductivity and formability matter. Yield strength is 310 MPa in H04 versus 80 MPa in O50.
Sources
- ASTM B747 / B152 (copper sheet, strip, plate and rolled bar) — ASTM International (2019)
- CDA UNS C15500 alloy datasheet (silver-bearing phosphorus-deoxidized copper) — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- GB/T 2059 / GB/T 2040 (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.