# Machining thin Aluminium washers



## Cyril H (Apr 4, 2021)

Going back about 64 years I was an apprentice and I had to produce some aluminium sealing washers for the aircraft industry.
Producing them and parting them off was not a problem but holding them to finish the parted face was. The foreman then explained how he had done a few years before.
An aluminium bar was held firmly in the chuck and a recess which located the washer but was not a tight fit was machined in the face. The recess was then filled with grease and the washer then bedded into it, with an extremely sharp tool and running at 1000 rpm it was possible to face it to size with very light cuts.


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## BaronJ (Apr 4, 2021)

Hi Guys,

I do very thin items using a "wax chuck" !  Basically an aluminum disc coated with shellac.


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## Tim Wescott (Apr 4, 2021)

Depending on the job, CA glue works well (AKA "superglue", but get at least hobby-store stuff).

It's strong in tension, brittle in shear, and sets up in no time flat.  So you can glue a thin workpiece to a flat face, then pop the piece off with a light rap of a hammer.  I'm not sure of the best way to locate a piece for repetitive work, but I can think of a couple of ways right off the bat, so it ought to be a solvable problem.


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## clockworkcheval (Apr 5, 2021)

If you are afraid of damaging the piece with a rap of the hammer, you also can dip the whole in boiling water. Superglues hold till about maximum 80 degrees Celsius, so it will float right of.


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## simonbirt (Apr 5, 2021)

Cyril H said:


> Going back about 64 years I was an apprentice and I had to produce some aluminium sealing washers for the aircraft industry.
> Producing them and parting them off was not a problem but holding them to finish the parted face was. The foreman then explained how he had done a few years before.
> An aluminium bar was held firmly in the chuck and a recess which located the washer but was not a tight fit was machined in the face. The recess was then filled with grease and the washer then bedded into it, with an extremely sharp tool and running at 1000 rpm it was possible to face it to size with very light cuts.


Interesting, I may give this a try, I have just made a batch of copper spark plug washers 1/4” ID and they are not easy to keep hold of. Thanks for the tip.


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## clockworkcheval (Apr 5, 2021)

In horology we hold thin brass wheels by soft-soldering them to a brass disc.


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## cheepo45 (Apr 5, 2021)

I have made a lot of washers using this technique.


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## goldstar31 (Apr 5, 2021)

I seem to like a hot glue gun.


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