Brass reference / Leaded brass
C377 forging brass
Hot forged to a near net shape then machined only where a sealing face or thread requires it.
Also known as Forging brass, Hot stamping brass, Alloy 377. Published typical values for the alloy, never a promise from a shop.
Composition
| Element | Nominal weight % |
|---|---|
| Copper | 58.0 to 61.0 |
| Lead | 1.5 to 2.5 |
| Iron | 0.30 max |
| Zinc | remainder |
Properties
- UNSC37700
- EN equivalentCuZn39Pb2 / CW612N
- Hardness60 to 80 HRB
- Density8.44 g/cm3
- Typical tolerance±0.05 mm as forged, tighter where machined
- Common formsForging billet and bar
What it is for, and what it is not
Specify it for
- Bulky parts made in real annual volume, roughly 5,000 pieces a year and up
- Valve bodies and heavy fittings
- Parts where most of the bar would otherwise become chips
- Parts that benefit from grain flow following the shape
Do not specify it for
- Low or uncertain volumes that cannot amortise a die
- Designs still likely to change
- Parts needing tight tolerance over most of their surface
- Wetted potable water parts
What a buyer should know
The point of C377 is what happens before machining. Its alpha-beta structure becomes highly plastic at forging temperature, so the part arrives near net shape and only the sealing features are cut. On a bulky part the material saved usually pays for the die several times over.
Nominal lead is 1.5 to 2.5 percent, which is above the 0.25 percent weighted average limit that NSF/ANSI 372 sets for wetted potable water surfaces. See NSF/ANSI 61 and 372 and RoHS exemption 6(c).
Dezincification resistance is poor, so this alloy is the wrong choice sitting in hot water or seawater regardless of how well it machines. See dezincification and the grades that resist it.
Closest alternatives
| Alloy | Lead % | Mach. | DZR | Why you might switch |
|---|---|---|---|---|
| C69300 silicon brassC69300 | under 0.09 | 80 | High | The usual lead-free answer for potable water, roughly twice as strong as C360 and highly dezincification resistant. |
| Bismuth brassC49300 / C49350 | under 0.25 | 80 | Moderate | Bismuth replaces lead as the chip breaker, so it behaves closest to C360 on an existing C360 program. |
| CW602N DZR brassNo direct UNS equivalent | 1.7 to 2.8 | 80 | High | A leaded brass with an arsenic addition and a controlled heat treatment, developed for European water fittings. |
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