Phosphor Bronze grade for boiler bushes

[Matt Stevens 1Participant @mattstevens1]

Hi All,

I am building the 6" vertical AJ Reeves boiler which calls for Phosphor bronze use on the bushes…. trouble is there are lots of grades out there. What type of PB should i be using?

I have heard there are drawn and cast grades – likely the latter is easier to machine on a lathe where i don't have coolant running. Another point is that i am based in Canada so a grade i can get in North America would be great…

Thanks

[Matt Stevens 1Participant @mattstevens1]

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Matt Stevens 1Participant @mattstevens1]

Posted by Bill Chugg on 13/04/2020 19:16:51:

PB102 is what I use.

Bill

Hi Bill – Isnt that the drawn stuff? Does it machine ok given i am not running coolant on my 9" lathe?

I have heard Calphos 90 mentioned alot as well….

[Matt Stevens 1Participant @mattstevens1]

I see C544 mentioned as a grade…any comments?

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Matt Stevens 1Participant @mattstevens1]

Thanks Bill….. i see that McMaster-Carr carry 510 and 544 grades. I believe 544 does have some lead in it, buts its more accessible and cheaper. If this is a suitable grade for boiler bushes then it might be a good bet.

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Matt Stevens 1Participant @mattstevens1]

Interesting how Bill's posts have been removed???

Anyway, from doing abit of research, it seems that PB102 is a common grade in the UK which is equivalent to C510 in North America. C544 is more common over here yet it doesnt seem that there is a comparable British Standard equivalent. See attached link for info…. **LINK** .

I still wonder if both C544 and C510 are ok for boiler use…..i would like to buy C544 which is far more accessible.

Thoughts?

[Thor 🇳🇴Participant @thor]

Hi Matt,

Doesn't C544 contain zinc and lead (in addition to tin)? If so it may not be as suitable as C510.

Thor

[Matt Stevens 1Participant @mattstevens1]

Yes i believe there is 4% lead in C544. Not sure about zinc…..Could you explain why you think this is a problem for boiler bushes?

I believe C544 is much easier to machine also than PB102/C510

[duncan webster 1Participant @duncanwebster1]

The spec for C544 is here **LINK** claims to be 'good' for brazing, so should be OK for silver solder as that is slightly lower temp.

It appears to be very similar to Colphos 90, **LINK** which machines a lot more easily than drawn PB102, which can be a right pig to drill and tap, it closes up on the drill.

 

Edited By duncan webster on 22/04/2020 15:42:56

[Thor 🇳🇴Participant @thor]

The subject was discussed earlier, see here.

Thor

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