You can still widen the pinch like.035" and run down a1/2" bit without going thru the casting.
You will however need a strong drill.
A 3/8" chuck model and one of those 1/2" bits that neck down to 3/8" will not get it done unles you use intermediate size bit before the 1/2".
If you still want more clearance at the top and have a chamfer bit or a unibit then use that some at the very top of the hole.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!
1) 1940s 100% silver 4 cup tea server set.
Two dry rotted 14 x 10 Micky Thompson slicks.
1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.
Education is what your left with once you forget things!
|