Drill/Reamer Combo

[Beem]

http://www1.mscdirect.com/CGI/NNSRIT2?PMPXNO=1704299&PMTERM=

 

Has anyone used these? I need to drill a 5/8" hole that's going to be holding a boring bar and need to keep it as on center as I can. I already looked into gundrilling and that would work, but I would need to remake the parts since they are tapered at one end and it gets too thin.

 

Any other ideas?

[Allan]

I've never seen/used one.

I would think the intended application was thinner material to save a tool change (like a drill tap does), not for any accuracy concerns. IMHO

If you are concerned about center location:

On a mill spot drill, then reamer size drill ~.015" undersize, then circular interpolate about .25" deep to .001" undersize then ream.

On a lathe spot drill, then reamer size drill ~.015" undersize, then bore about .25 deep to .001" undersize, then ream, or just bore the whole thing depending how deep.

 

HTH

 

Allan

[Beem]

Thanks for the advice. I'll give it a shot running it in a mill.