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View Full Version : Do you drill a pilot hole first?

zappy
10-06-2008, 01:16 AM
I saw someone hammerdrill a small pilot hole through the concrete wall first,then he used the 1" bit,anyone else prefer this way?Reasons?
Minuteman
10-06-2008, 01:21 AM
I've used that method, sort of. I drilled the small hole on the "pretty" side, and then the large hole going the other direction where it didn't matter if I blew it out.
BLACK4TRUCK
10-06-2008, 01:56 AM
I always drill a smaller hole first and then go to a larger bit. I think the bit drills faster this way because you won't hit a rock with the drill point. The smaller bit has less trouble breaking up stones.
LarryFine
10-06-2008, 02:01 AM
It also gives the debris a place to go beside up the flutes.

I do the same thing with high-speed bits in hard metals.
ElectricianJeff
10-06-2008, 06:03 AM
I do when I want to know "exactly" where I will be coming out on the other side.
GUNNING
10-06-2008, 11:09 AM
till its small enough?
I do if its an underpowered drill and a big hole. It removes some of the material before the big bit gets there. saving wear and tear on the drill motor. It makes a good guide hole for the big bit to follow. It reduces the heat wear and tear, exerted on the big EXPENSIVE bit. If you only have a shorter large bit, but a longer smaller bit, you can drill from both sides and not miss using a pilot hole with the smaller longer bit. If your not sure whats in the wall, re bar cast vent pipe plumbing etc., a small bit is a small hole to move and fix and replace.

All good reasons to use a pilot hole.

Have I missed anything?
ultramegabob
10-06-2008, 03:36 PM
I've used that method, sort of. I drilled the small hole on the "pretty" side, and then the large hole going the other direction where it didn't matter if I blew it out.

same here....
Cow
10-06-2008, 09:24 PM
I saw someone hammerdrill a small pilot hole through the concrete wall first,then he used the 1" bit,anyone else prefer this way?Reasons?

Yes. Smaller blowout with a 1/4" pilot, then hit it from both sides with the 1" to keep the hole looking good. A pilot will sometimes let you know if there's rebar in the way too. Plus, a 6" wide blowout from a 1" hole looks terrible...:mad: