Bell Metal – What is it good for?

[Grindstone CowboyParticipant @grindstonecowboy]

Hi Folks

I know there are some campanologists on here, so maybe you could help, along with the metallurgists…

Via a bell-ringing friend, I am about to acquire a few lumps of bell metal – don't worry, it's all legal, they are apparently fitting new crowns(?) and this is part of what's been cut off to do so.

He has been told it is (most likely) 77% copper and 23% tin. My question is, what might it be good for for a home machinist? I believe it was very hard to cut, which is slightly putting me off.

I know the ideal is to buy proper machinable materials, but, hey, it's free!

Thanks, Rob

[Grindstone CowboyParticipant @grindstonecowboy]

Absolutely nothing? Or just bells?

[not done it yetParticipant @notdoneityet]

I don’t know about use other than for bells – where it has an extremely good scrap re-cycle value!

[Howard LewisParticipant @howardlewis46836]

Sounds like a copper rich relative relative of brass?

Howard

[old martParticipant @oldmart]

It would make good bushes like bronze or brass.

[Grindstone CowboyParticipant @grindstonecowboy]

Posted by Howard Lewis on 25/08/2023 21:22:07:

Sounds like a copper rich relative relative of brass?

Howard

Or, looking at Wikipedia, a tin rich relative of bronze which apparently runs at around 12% tin, plus traces of other metals. Their article on bell metal is actually quite interesting, and mentions cannons, valve bodies, piston rings, bearings, and bushings, so maybe it could come in useful

As far as I know, the bells are from around 1870, when (allegedly) they were cast by "digging a hole in a field and pouring molten metal in" – I'm sure it must have been a bit more complex than that!

Rob

Edit – thanks, Old Mart, you posted whilst I was typing – bushes and bearings seem to be favourite, then. Once I get hold of it, I'll hack off a bit and see how well it machines – I'm thinking possibly carbide tooling may be necessary.

Edited By Grindstone Cowboy on 25/08/2023 21:45:22

[noel shelleyParticipant @noelshelley55608]

It is quite brittle ! Best used to cast with. Recast as a bell, it should have a good tone. The history of bells and their casting is quite interesting. Noel.

PS A trip to John Taylors Bell foundry is a good day out, the more so if you go on a day when their pouring bells. n

Edited By noel shelley on 25/08/2023 22:27:08

[Grindstone CowboyParticipant @grindstonecowboy]

Thanks Noel

I don't think I'm getting enough to make a bell with, unfortunately. From the little I've read on the subject so far, you are quite correct, a bit of a black art.

Rob

[John Doe 2Participant @johndoe2]

Where I used to be Tower Captain; we augmented our six church bells to eight and had our two extra bells cast at the Whitechapel bell foundry, before it closed.

We were allowed to visit and watch our bells being 'poured', if that's the right term. The moulds are made inside metal cases from a clay mixed with animal hair, which burns away, leaving tiny air passages for gasses to escape. A fascinating process, and we also had all eight bells tuned in a giant vertical lathe, where they remove metal from the inside surface in certain bands to tune about 5 separate notes on each bell. Our largest bell weighed 14 and-a-bit cwt before tuning, and under 14 cwt after, so quite a lot of metal removed.

I don't know what else you could use bell metal for – casting a door bell maybe?

[bernard towersParticipant @bernardtowers37738]

went to a bell foundry in Italy that does founding for the Vatican and they still dig holes in the floor and line with clay and animal hair. Same set up for centuries.

[Neil AParticipant @neila]

I think that you will find that the high tin content will make it a difficult material to machine, certainly carbide would be my choice if I had to machine bell metal.

It is not a material I would consider for making bearings, it is much too hard and brittle. It would have no confirmability to the journal surface.

Most bearing alloys have between 4 and 11% tin, not the 22% of bell metal. it is approaching the composition of Speculum Metal used for telescope mirrors up to the mid 1800's.

Best use for bell metal is probably bells.

Neil

[BazyleParticipant @bazyle]

If you are thinking of casting it into a more useful shape, eg round for bearings, just add some more copper which is much more readily available than tin.

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