Machining copper

[Trevor RobertsParticipant @trevorroberts83547]

HI

Can anyone advise on machining copper. I am working on a boiler and I have trim some plates in the lathe, would I use the same shape of tool as for machining brass?

I also have to drill a large number of holes, what would be the best drill bit shape. Should I modify the drill bits as if I was drilling brass?

I obviously don't want to 'tear' or otherwise damage my prepared copper plates/barrel.

Thanks in advance.

Trefor

[Trevor RobertsParticipant @trevorroberts83547]

[JasonBModerator @jasonb]

A tool with more top rake will work better like you would use on aluminium or a **GT insert if you prefer inserts.

For larger holes to take bosses and firetubes I would go with a step drill and have never bothered to alter smaller twist drills for brass, bronze or copper.

Full fat milk makes a good cutting fluid.

[nigel jones 5Participant @nigeljones5]

As a full time copper boiler maker I do quite a bit of this…..I only ever use CCGT tips (as per JB) for turning copper as they out perform everything else by a country mile – no grabbing and clean cuts. Standard drills are fine but beware that your holes will all come out slightly under size. You need to lubricate when drilling copper, and it gives a better cut when turning, I use wd40 as it does the whole machind good and doesnt smell bad. Good luck!

[Martin KyteParticipant @martinkyte99762]

Lots of rake. Definitely not zero or negative rake as for Brass.

Drilling holes, twist drills ground to a brad point wood bit form work well. The sort with a central triangular bit in the middle and the corners proud so they start cutting before the flanks. This gives a clean hole with no burr on the reverse side.

regards Martin

[old martParticipant @oldmart]

It's always a good idea to try the recommended tooling on any offcuts of the metal first to get a feel for yourself. That way there will be no danger of spoiling the actual workpiece.

[Trevor RobertsParticipant @trevorroberts83547]

Thanks everybody for your replies. I'm going down to the workshop now to do some tests/practice on some scrap copper.

Thanks again

Trefor

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