Articles
Notes on brass, machining, and the rules that apply to it.
One question per article, answered with numbers from mill certificates and the shop floor.
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PT, PF and NPT: Reading Old JIS Pipe Thread Callouts
What the old Japanese pipe thread names mean, why a 1/2 PT and a 1/2 NPT can pass for the same thread, and what to write on the drawing instead.
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Leaded Brass and the US 0.25% Lead Rule
What free-cutting brass actually contains, what the lead-free alternatives cost to machine, and how to tell whether the rule applies to your part.