"MinorMania" wrote in message
...
| Hi All
|
| I need to enlarge the mounting holes in a set of cast aluminium wheels
from
| 5/8 to 17.5mm. I have a new reduced shank drill that I am using in an air
| drill (hand held) as I don't want to demount the tyres.
|
| I'm finding the drill is grabbing quite badly in the soft aluminium. I
found
| in a search that you can 'stone' the drill to stop this happening, or at
| least make it better. I'm curious about which part of the drill should get
| this treatment though. The cutting lips, or ???
|
| Thanks, Trev.

First off, put some lube in there. Secondly, don't push. Keep a firm
grip on the drill so that it doesn't want to get ahead of you or away. Spin
it up fast before you enter the hole and don't push when it's in a spot
where it wants to bind up. Let the drill bit clip off the burr that comes
from getting too big a bite then go in easy.
If you can step up in size to where you want to be you'll get a good
clean hole with less binding as will happen from a single drill bit.