Rubbish Milling Finish in Aluminium

[Oily RagParticipant @oilyrag]

Avon,

Well with the silicon content in LM25 if heat treated correctly – including the tempering quench in just off boiling water (90C) it should give a good acceptable finish. having said that though the embedded sand in the riser will also not help the finish or the cutter!

As Jason suggested earlier – try a decent piece of known billet, avoid 2018 though.

Martin

[John ReeseParticipant @johnreese12848]

As Journeyman said it looks like a dull cutter. In addition it looks like chip welding to the cutter. Cutting lube would prevent chip welding. the metal itself is cast. I suspect it is of unknown composition. The metal itself could be the cause of tearing.

[HopperParticipant @hopper]

Posted by Oily Rag on 29/03/2021 23:38:20:…

…As Jason suggested earlier – try a decent piece of known billet, avoid 2018 though.

+2 on that. Waste of time trying to machine a bit of old scrag from a riser full of impurities and sand and untempered. Get a good bit of known grade ally, preferably square or rectangular to sit nicely in the vice. Or even a bit of known quality mild steel flat bar etc.

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