Cartridge Brass C26000
The 70-30 brass for cold-headed and formed hardware — 60 to 90 ksi as a fastener under F468, with deep-drawing ductility.
What C26000 Brass is.
Cartridge brass C26000 is the 70 percent copper, 30 percent zinc alpha brass named for its use in ammunition cases. It is the most ductile of the common brasses and work-hardens strongly, so cold-headed screws, rivets and formed hardware reach useful strength without any heat treatment. It resists atmospheric and fresh-water corrosion but is susceptible to stress-corrosion cracking in ammonia and to dezincification in aggressive water.
ASTM F468 covers C26000 fasteners as Cu 260 (marking F468AB). We supply cold-headed and machined C26000 hardware to F468 and F467.
Chemical composition.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Copper | Cu | 68.5 | 71.5 |
| Iron | Fe | — | 0.05 |
| Lead | Pb | — | 0.07 |
| Zinc | Zn | balance | — |
Values per ASTM F468-23 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 | 55–80 HRB | 60–90 | 50 | 55 | 50 | 35 |
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 | 55 HRF | 60 |
| Heavy hex, large hex flange and thick | 55 HRF | 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 C26000 Brass ships from Houston.
- Cold-headed screws, rivets and studs to F468
- Nuts to F467
- Formed and machined brass hardware
- Electrical and decorative components
C26000 Brass fasteners we make.
Every item is manufactured to your drawing or standard in C26000 Brass, imperial or metric, with an EN 10204 3.1 certificate.
What is cartridge brass?
C26000 sits at the copper-rich end of the brass range where the structure is entirely alpha phase. That single phase is what makes it so ductile: it can be deep drawn, spun and cold headed through large reductions, hardening as it goes. Fasteners made by cold heading therefore arrive at 60 to 90 ksi with no heat treatment at all. Machinability is only about 30 percent of free-cutting brass, so turned parts are normally made in C36000 instead.
Handling notes
Highly cold-worked 70-30 brass can crack in service in the presence of ammonia or moist ammonium compounds, a phenomenon known as season cracking; a low-temperature stress relief after forming removes the risk. Avoid the alloy in aggressive or acidic waters where dezincification is likely.
Testing, certification and marking
- Tensile and hardness tested per lot on the finished product
- Grade or alloy marking F468AB on bolts and F467AB 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
Free-Cutting Brass C36000
The fastest-machining engineering metal — 3 percent lead brass for turned fittings, terminals, valve parts and volume screw-machine work.
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).
ASTM F468 / F467 fasteners · ASTM B98 rodLow-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.