Copper Alloy C53800-HR50
Supply condition
UNS C53800
HR50 = cold drawn and stress-relieved / light anneal
Cold-drawn bar given a low-temperature stress relief to stabilise dimensions before precision machining.
Values for the HR50 condition
Other C53800 tempers and conditions
C53800 is listed in 8 conditions; see the grade overview at C53800.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for maximum ductility, bending or subsequent cold forming of rod and strip. | 150 | 350 | 40 | 70 HB | — |
Quarter hard | Light cold work when moderate strength must be combined with residual bending ductility. | 290 | 420 | 25 | 118 HB | 15 % IACS |
Half hard | Common screw-machine stock balance of strength, straightness and some formability. | 380 | 480 | 15 | 145 HB | 15 % IACS |
HR50This page Cold drawn and stress-relieved / light anneal | Cold-drawn bar given a low-temperature stress relief to stabilise dimensions before precision machining. | 440 | 520 | 10 | 158 HB | 15 % IACS |
H04Default Full hard | Standard stocked cold-drawn rod temper for turned bushings, valve parts and machined fittings. | 450 | 540 | 8 | 165 HB | — |
Extra hard | Higher cold work for stiffer small-diameter rod/wire and light spring contacts. | 520 | 600 | 5 | 12 HRC | 15 % IACS |
Spring hard | Spring-hard wire/strip where machined-then-formed elastic elements are required. | 580 | 650 | 4 | 16 HRC | 15 % IACS |
Extra spring hard | Maximum cold-worked strength for small-section spring wire; very limited bend ductility. | 620 | 690 | 3 | 18 HRC | 15 % IACS |
What is C53800-HR50?
C53800-HR50 is C53800 supplied in the HR50 condition — cold-drawn bar given a low-temperature stress relief to stabilise dimensions before precision machining. C53800-HR50 has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 85% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 110 GPa (16 Msi). C53800-HR50 has a density of 8.86 g/cm³ (0.32 lb/in³), heavier than 68% of copper alloy grades. It melts at 930°C (1,706 °F). H04 is the default condition FabDigit quotes; HR50 is available on request or by drawing note.
Advantages
- Easy to machine — 80/100, better than 86% of copper alloy grades
- High strength — 440 MPa (63.8 ksi), better than 85% of copper alloy grades
Limitations
- Difficult to weld — 20/100, worse than 88% of copper alloy grades
- Limited ductility — 10%, worse than 76% of copper alloy grades
C53800-HR50 properties
Typical room-temperature values for C53800-HR50; 18 are specific to this condition. Other listed values are C53800 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C53800-HR50 has a density of 8.86 g/cm³ (0.32 lb/in³), heavier than 68% of copper alloy grades. It melts at 930°C (1,706 °F).
Mechanical12
C53800-HR50 has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 85% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
C53800-HR50 is rated for continuous service to 210°C (410 °F). It conducts heat at 69 W/m·K (39.9 BTU/hr·ft·°F), worse than 56% of copper alloy grades. Thermal expansion is 17.8 µm/m·K (9.89 µin/in·°F).
Electrical3
C53800-HR50 conducts electricity at 15 % IACS, worse than 54% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C53800-HR50 takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 45%.
Manufacturability7
C53800-HR50's machinability is very good (80/100, better than 86% of copper alloy grades); weldability poor (20/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C53800-HR50
Is C53800 easy to machine?
Excellent on automatic screw machines — lead breaks chips; use sharp positive-rake carbide or HSS, high speed, light-to-medium feed and soluble oil.
Can C53800 be welded?
Not recommended for fusion welding (lead causes hot cracking); join by soft soldering or mechanical fastening, braze only with care and low lead exposure.
Can C53800 be formed, bent or molded?
Cold bending and light heading are possible in O61/H01 tempers; avoid hot working — lead makes the alloy hot-short above ~300 °C.
What surface finishes work on C53800?
Takes bright turning and buffing well; tin, nickel or silver plating is standard for contacts, and clear lacquer or patina prevents tarnish.
C53800 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 |
|---|---|---|
| Snprincipal solid-solution strengthener | 4 – 6 | 5 |
| Pbfree-machining addition; higher than C53400 | 1 – 2 | 1.5 |
| Pdeoxidiser, residual | 0.03 – 0.35 | 0.15 |
| Zn | ≤ 0.3 | — |
| Fe | ≤ 0.1 | — |
| CuCu + named elements ≥ 99.5 %; verify exact limits against the governing ASTM B139/B103 registration and the mill certificate | balance | — |
C53800-HR50 — frequently asked
What is C53800-HR50 used for?
C53800-HR50 is typically used for bushings, washers and machined fittings. In short: best-machining phosphor bronze; screw-machine bearing stock; cold work only.
What is the yield strength of C53800-HR50?
C53800-HR50 has a typical yield strength of 440 MPa (63.8 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 85% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C53800-HR50 easy to machine?
Yes — machinability is rated very good (80/100, better than 86% of copper alloy grades). Excellent on automatic screw machines — lead breaks chips; use sharp positive-rake carbide or HSS, high speed, light-to-medium feed and soluble oil.
Can C53800-HR50 be welded?
Not readily — weldability is rated poor (20/100). Not recommended for fusion welding (lead causes hot cracking); join by soft soldering or mechanical fastening, braze only with care and low lead exposure.
What surface finishes work on C53800-HR50?
Takes bright turning and buffing well; tin, nickel or silver plating is standard for contacts, and clear lacquer or patina prevents tarnish.
Can C53800-HR50 be formed, bent or molded?
Cold bending and light heading are possible in O61/H01 tempers; avoid hot working — lead makes the alloy hot-short above ~300 °C.
What is the maximum service temperature of C53800-HR50?
C53800-HR50 is rated for continuous use to about 210°C (410 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C53800-H04 and C53800-O61?
H04 is the default condition — standard stocked cold-drawn rod temper for turned bushings, valve parts and machined fittings. O61: softest condition for maximum ductility, bending or subsequent cold forming of rod and strip. Yield strength is 450 MPa in H04 versus 150 MPa in O61.
Sources
- ASTM B139/B139M — Phosphor Bronze Rod, Bar and Shapes — ASTM International (2017)
- CDA Standard Designation & Alloy Property Data (C5xxxx phosphor bronzes) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.