CW614N (CuZn39Pb3, ~3% Pb) is the free-machining champion — machinability 100, but cold formability rated "Poor". CW617N (CuZn40Pb2, ~2% Pb) is the forging and hot-stamping grade — machinability a notch lower in the ~85–90 band, cold formability "Limited" (better than CW614N), and it is the benchmark stock sold for hot-pressed parts. Machining shops default to CW614N; parts that are forged to near-net shape and then machined use CW617N.
These are the two most-confused brasses on any drawing. They look almost identical on paper — both roughly 59% copper, 39% zinc — yet they are optimised for different processes. Get the choice right and you save cost; get it wrong and you either lose machinability you did not need to, or try to cold-form an alloy that will crack.
Both figures live on the same scale
CW614N and CW617N are both rated on the copper-alloy machinability scale (C36000 = 100), so their machinability numbers here are directly comparable.
CW614N vs CW617N: the numbers side by side
| Property | CW614N (CuZn39Pb3, CZ121) | CW617N (CuZn40Pb2, CZ122) |
|---|---|---|
| Nominal composition | ~59% Cu, ~39% Zn, ~3% Pb | ~59% Cu, ~39% Zn, ~2% Pb |
| Machinability (copper-alloy scale) | 100 — the highest machinability of any copper alloy | ~85–90 (canon ~90; one datasheet quotes 85%) |
| Hot formability (hot stamping / forging) | "Excellent" (working ~625–725 °C) — but not the dedicated forging stock | "Excellent" (working ~650–775 °C); the benchmark hot-stamping / forging brass |
| Cold formability / ductility | "Poor" — higher Pb & β-phase reduce cold ductility | "Limited" — better than CW614N, still not a cold-forming alloy |
| Cold-forming ops (rivet / stake / crimp / bend) | Avoid — poor cold ductility; not suited to riveting / staking / heavy bending | Better tolerated than CW614N, but still limited |
| Typical EN standard / product form | EN 12164 (rod for free-machining) | EN 12164 (rod) / EN 12165 (forging stock) / EN 12163 — largely supplied as forging stock |
| Primary use | High-speed, high-volume precision machining (turned fittings, connectors) | Hot-stamped / forged bodies then machined; complex net-shape parts |
A key clarification on "which forges better": both grades hot-work well — both are rated "Excellent" for hot formability. The distinction is that CW617N is the standard stock sold for hot stamping and forging; its slightly lower lead and better ductility make it the safer choice for parts that undergo significant hot deformation and then demanding machining. CW614N is optimised purely for machining and is chosen when the part is turned or milled from bar with little or no forming. Some general references loosely call CW614N a common hot-stamping alloy too, but the practical trade convention is CW617N = forging grade, CW614N = machining grade.
Decision block — pick one if…
Pick CW614N (CuZn39Pb3) if…
The part is machined from bar — turned or milled — with no significant cold or hot forming; you want absolute best machinability, tool life and cycle time (it is the 100 datum); higher lead, around 3%, is acceptable for the application and market; and you do not need to rivet, stake, crimp or heavily cold-bend the part, since its cold ductility is "Poor".
Pick CW617N (CuZn40Pb2) if…
The part is hot-stamped or forged to near-net shape and then machined — its home turf, supplied as EN 12165 forging stock; you need somewhat better ductility or hot-working behaviour, or want the lower ~2% lead for a slightly lower-lead spec; the part is a complex body such as a valve or fitting body where forging grain flow plus post-machining is the process; and you can accept a small machinability drop, roughly 85–90 versus 100, in exchange for forgeability.
How Brassland fits in
We machine both grades and forge through qualified partners. See the CW614N datasheet and the CW617N datasheet for full properties. For turned-from-bar parts we default to CW614N on our Swiss turning lines; for forge-then-machine parts we use CW617N via hot forging and then finish the critical features in-house. If you need a genuine cold-forming grade, neither of these is the right answer — ask and we will point you to a lower-lead, higher-copper alloy.
Frequently asked questions
What is the real difference between CW614N and CW617N?
Can I cold-form, rivet or stake CW614N?
Which one is better for forging?
Is CW617N harder to machine than CW614N?
Are CW614N and CW617N interchangeable on a drawing?
Sources & references
Figures on this page are drawn from published alloy datasheets, standards bodies and engineering references. Key sources:
Last reviewed: July 2026. Material and process figures are checked against datasheet and standards references at each review. Cross-material machinability numbers are indicative (see note in the article), not two points on one physical scale.
Need this part in the right alloy?
Brassland machines precision brass, copper and aluminium components to your drawing — Swiss turning to ±0.005 mm, CNC machining in-house, and hot forging through qualified partners. Send a drawing and we will get back to you.
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