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.
What C65500 Silicon Bronze is.
C65500 carries about 3 percent silicon and 1 percent manganese. It is the general-purpose wrought silicon bronze, stronger than C65100 in bar form and available in tempers from soft to extra-hard, with the same excellent resistance to seawater, sulfite liquors and mild acids. It is easily welded and machines well for a bronze.
ASTM F468 lists C65500 fasteners as Cu 655 (marking F468L). We machine C65500 studs, bolts, nuts and components from certified B98 rod in the temper the job needs.
Chemical composition.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Copper | Cu | balance | — |
| Silicon | Si | 2.8 | 3.8 |
| Manganese | Mn | 0.50 | 1.3 |
| Iron | Fe | — | 0.8 |
| Zinc | Zn | — | 1.5 |
| Nickel | Ni | — | 0.6 |
| Lead | Pb | — | 0.05 |
Values per ASTM B98/B98M-13(2019) Table 1 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
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 | 60–80 HRB | 50–80 | 20 | 50 | 15 | 20 |
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 | 50 |
| Heavy hex, large hex flange and thick | 60 HRB | 54 |
Values per ASTM F467-24 Table 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
| Temper and size (in.) | Tensile strength, min (ksi) | Yield strength at 0.5 % extension, min (ksi) | Elongation, min (%) |
|---|---|---|---|
| O60 soft anneal — all sizes | 52 | 15 | 35 |
| H01 quarter-hard — all sizes | 55 | 24 | 25 |
| H02 half-hard — to 2 | 70 | 38 | 20 |
| H04 hard — to ¼ | 90 | 55 | 8 |
| H04 hard — over ¼ to 1 | 90 | 52 | 13 |
| H04 hard — over 1 to 1½ | 80 | 43 | 15 |
| H04 hard — over 1½ to 3 | 70 | 38 | 17 |
| H06 extra-hard — to ½ | 100 | 55 | 7 |
Values per ASTM B98/B98M-13(2019) Table 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
Specifications that apply.
How C65500 Silicon Bronze ships from Houston.
- Machined hex bolts, studs and cap screws to F468
- Hex and heavy hex nuts to F467
- Valve stems, pump shafts and marine components to print
- Certified B98 rod and bar in the temper ordered
C65500 Silicon Bronze fasteners we make.
Every item is manufactured to your drawing or standard in C65500 Silicon Bronze, imperial or metric, with an EN 10204 3.1 certificate.
What is high-silicon bronze?
C65500, sold historically as Everdur and Herculoy, is copper with about 3 percent silicon and 1 percent manganese. The silicon raises strength to that of mild steel in the hard tempers while leaving the corrosion resistance and colour of bronze intact. It is the most common silicon bronze in bar and plate and one of the most weldable copper alloys.
Fastener requirements versus bar tempers
The F468 requirements for C65500 fasteners are conservative because they cover product that may be hot forged or annealed: 50 to 80 ksi tensile with 20 ksi yield and 60 to 80 HRB. Fasteners machined from hard-temper bar can be certified to the bar properties instead, up to 90 ksi tensile and 52 ksi yield in sizes to 1 inch; tell us which document your specification invokes.
Testing, certification and marking
- Tensile and hardness tested per lot on the finished product
- Grade or alloy marking F468L on bolts and F467L 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
Recent C65500 Silicon Bronze jobs.
Low-Silicon Bronze C65100
The silicon bronze for cold-headed screws and bolts — 70 to 100 ksi in small sizes under F468, with the corrosion resistance and warm colour of bronze.
ASTM F468 / F467 fasteners · ASTM B150 rod and barNickel-Aluminum Bronze C63000
Steel-like strength in a bronze — 100 to 130 ksi as a fastener — with seawater, cavitation and wear resistance for propellers, pumps, valve seats and subsea hardware.
ASTM F468 / F467 fasteners · ASTM B150 rod and barAluminum Bronze C61400
The 7 percent aluminum bronze — 75 to 110 ksi as a fastener, weldable, and resistant to seawater, brine and dilute acids.