"Baz" wrote in message
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Dave Plowmans method for Annealing is the way to go.

"Annealing ally is easy. Wipe it with soap - the sort you clean your face
with - and heat it 'till the soap turns black. Then quench in water."

However, if you want to put a thread in annealed aluminium, use a three-lobe
displacement tap, not a convential tap that cuts the threads. Three-lobe
taps work harden the material locally, making the thread stronger than if
you cut it.

Colin Bignell