Types of bronze for steam piston

[Minibrix]

I am building LSBC's steam fire engine which has a 1/2" brass cylinder, I have made a brass piston but want to replace it with a bronze one. I am confused about which type of bronze to use as I've seen types PB102, PB106 and aluminium bronze. which type is would be most suitable ?

 

[GailInNM]

My choice would be C93200, also known as C932, SAE660 or 932. It ie easily available from most industrial suppliers as well as metal vendors for about US$10 per foot for 1/2 nominal diameter. Normally supplied about 1/32 inch oversise for machining to size. Very easy to machine and my 'go to' material for common bronze parts.
Gail in NM

 

[Minibrix]

Thanks for the info Gail, have checked and it is widely available in UK.