hi bob,

i would agree with russell, with the addition that hard drawn phos bronze is best. however hard drawn phos bronze is quite difficult to get these days – you might be lucky! the modern phos bronze is sort of cast and the threads arent so strong. ive used it for large bushes such as dome flanges etc. smaller stuff i prefer hard drawn phos bronze though im rapidly running out of it! it silver solders ok though. dont ever use ali bronze for bushes on boilers silver soldered. save it for coupling and conn rod bearings. martin evans used to specify gunmetal but i dont like to use gunmetal for silver soldered boiler bushes as it can be porous and of indifferent quality and the threads arent very strong in our ME sizes.

cheers,

julian

There are data sheets on a number of bronze types here including 2 gun metals

**LINK**

I might build a steam plant at some point and from looking at these and others intend to use SAE660 bronze. It should be readily available and well priced – I hope.

I've resisted making a steam engine for a long long time but I'm getting tempted but one or two more tools first.

John

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