Phosphor Bronze C51000 / C54400
The spring and fatigue bronze — 5 percent tin with phosphorus for elasticity, wear and corrosion resistance; C54400 is the free-machining version.
What C51000 Phosphor Bronze is.
Phosphor bronze C51000 is copper with about 5 percent tin and a trace of phosphorus left from deoxidation. Tin strengthens and hardens the copper and gives the alloy its outstanding fatigue and spring properties; phosphorus improves wear resistance and stiffness. C54400 is the same base alloy with 4 percent lead and zinc for free machining, and is the usual choice for turned bushings and fasteners.
ASTM F468 lists C51000 fasteners as Cu 510 (marking F468E). We supply phosphor bronze fasteners and machined components in both alloys from certified B139 rod.
Chemical composition.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Copper | Cu | balance | — |
| Tin | Sn | 4.2 | 5.8 |
| Phosphorus | P | 0.03 | 0.35 |
| Iron | Fe | — | 0.10 |
| Zinc | Zn | — | 0.30 |
| Lead | Pb | — | 0.05 |
Values per ASTM F468-23 Table 1 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team. C54400 (free-cutting phosphor bronze) adds lead and zinc; consult ASTM B139 for its limits.
Mechanical properties.
| Nominal diameter (in.) | Hardness | Full-size tensile (ksi) | Full-size yield, min (ksi) | Machined tensile, min (ksi) | Machined yield, min (ksi) | Elongation in 4D, min (%) |
|---|---|---|---|---|---|---|
| All sizes | 60–95 HRB | 60–90 | 35 | 55 | 30 | 15 |
Values per ASTM F468-23 Table 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team. Full-size tensile range and yield; machined-specimen minimums in the last three columns.
| Nut style | Hardness, min | Proof stress, min (ksi) |
|---|---|---|
| Hex and hex flange | 60 HRB | 60 |
| Heavy hex, large hex flange and thick | 60 HRB | 65 |
Values per ASTM F467-24 Table 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
Specifications that apply.
How C51000 Phosphor Bronze ships from Houston.
- Bolts, studs and screws to F468
- Nuts to F467
- Bushings, bearings, gears and wear parts machined from C54400
- Springs and electrical contacts
- Certified B139 rod
C51000 Phosphor Bronze fasteners we make.
Every item is manufactured to your drawing or standard in C51000 Phosphor Bronze, imperial or metric, with an EN 10204 3.1 certificate.
What is phosphor bronze?
Phosphor bronzes are copper-tin alloys deoxidised with phosphorus. C51000, the 5 percent tin grade, combines good strength with the best fatigue resistance of the common copper alloys, which is why it is the standard for springs, contacts and any bronze part that flexes. Corrosion resistance in fresh water, mild acids and the atmosphere is excellent, and the alloy is non-magnetic and non-sparking.
C51000 or C54400?
C51000 is the wrought spring grade and the alloy F468 covers for fasteners. C54400 adds about 4 percent lead and 4 percent zinc, raising machinability to 80 percent of free-cutting brass with a small loss of strength and ductility; it is the grade to specify for turned bushings, gears and screw-machine components. Both share the same corrosion behaviour.
Testing, certification and marking
- Tensile and hardness tested per lot on the finished product
- Grade or alloy marking F468E on bolts and F467E on nuts and manufacturer's identification on every piece
- EN 10204 3.1 material test report with heat number and chemistry; 3.2 witness available
- Alloy identified by UNS number on the certificate
High-Silicon Bronze C65500
The strongest common silicon bronze in bar form, 90 ksi in hard temper and 100 ksi extra-hard in small rod — for machined marine fasteners, valve stems and pump parts.
ASTM B505 continuous-cast barBearing Bronze C93200 (SAE 660)
The workhorse bearing bronze — SAE 660 — for bushings, thrust washers and wear parts machined from continuous-cast bar.
ASTM F468 / F467 fasteners · ASTM B21 rod and barNaval Brass C46400
The marine brass — 1 percent tin for seawater resistance — and the ASTM F468 structural brass fastener alloy (F468D).