Machining gun metal

[Eric CoxParticipant @ericcox50497]

When machining gun metal should it treated the same as brass and cut at a high speed

[Eric CoxParticipant @ericcox50497]

[Neil WyattModerator @neilwyatt]

Gunmetal is generally a very well-behaved metal! It machines better than bronze but isn't as prone to lots of needle like chips as with brass. You are best approaching it as if it was a very free-cutting mild steel and I wouldn't recommend zero-rake flat topped tools that you might use for brass. Because 'gunmetal' covers a lot of ground (generally most copper/zinc/tin alloys there's fair bit of variation.

Neil

[Mick B1Participant @mickb1]

Many of the bits I make for the local railway are in LG2 – leaded gunmetal. I treat it the same as CZ121 brass and don't meet any issues I can readily think of. Batches are small, typically 4 – 12 components, so maybe I'm not doing enough to expose any real differences.

[Thor 🇳🇴Participant @thor]

Hi Eric,

I have machined LG2, and as Mick I run the work at about the same speed as you would for free cutting brass.

Thor

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