Thread: HSS tool reccomendations for boring job

Are you going to use the HSS in a boring bar or just use it in the tool post?

Because the job is so shallow I was thinking of just using HSS in the toolpost.

I have 1/2, 3/8, 5/16, 1/4 and 3/16 HSS at my disposal.

Which piece of HSS will cover the width of the tool post and still allow for enough depth to do the job,the more tool post clamps the better.

Either the 1/2 inch or the 3/8

Use the 3/8 it will take a little less grinding.
You may have to grind 2 cutting edges if you cant grind something that will bore/turn and face.
Unless you can find a drawing on the net of a suitable tool ground for cutting Aluminium it will be a bit awkward to describe.
You need the tool fairly sharp with a fair amount of top rake.
You will have to grind enough side rake/clearance so that the tool does not rub as it machines the bore.
Front clearance angles should be enough to give clearance so not to rub as you bore ( looking down on the tool from above you want the edge that will be cutting to just have a little,the front of the tool slightly more).
In essence you will be trepaining.
The tool will be similar to a parting tool shape.
When you come to do the finish face just grind a knife tool up,feed from the centre out,when you get to the edge just under cut it slightly so as to get rid of any square corner or radious thats not desired.

G'Day Brendan,
I regularly do a job that is similar to the one you describe, I use an 8mm SECO boring bar with a CCMT insert and slightly undercut the inner corner.
Regards,
Martin