Turning aluminium with carbide inserts

[not done it yetParticipant @notdoneityet]

Vic,

Read Andrew’s post just above yours. That should make it clear enough.

[John ReeseParticipant @johnreese12848]

Vic,

You could grind a chipbreaker into the tool but I doubt it would work well. Wrought aluminum doesn't break up for me. I notice the polished inserts for aluminum don't have a chipbreaker. Cast aluminum does break chip fairly readily. Unfortunately the high silicon content dulls HSS quite rapidly.

[John ReeseParticipant @johnreese12848]

Vic,

Something I forgot to mention: the way a tangential tool is positioned it might be difficult to get an effective chipbreaker. There is a very small clearance angle on the tool. If you ground a groove for a chipbreaker I suspect there might be interference between the ridge behind the groove and the work. Be advised that my conclusion was arrived at in my recliner, not in my shop.

[Anonymous]

Posted by Vic on 19/01/2019 12:11:41:

…..have any of you milled HSS tool bits with a carbide end mill? Just wondering if it's preferential than grinding the initial shape in some cases?

Yep:

Involute form milled on the end of a 1/4" square HSS toolbit with an uncoated 3-flute carbide cutter, for use with a slotting head to cut an internal gear. Relief and rake angles were ground by hand afterwards.

If I need to remove a lot of material to get the required shape I'll rough out with a carbide cutter to start with. Way quicker than grinding.

Andrew

[Author]

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