I'm working on a project where I have a 3/4" thick piece of wood. I need to drill all the way through to install a bolt, but I want the head of the bolt to sit slightly recessed inside the wood. I can easily drill through, but I need to create a flat recess for the bolt head so it doesn't stick out. I've seen countersink bits, but they don't seem right for a flat head bolt. What type of bit can I use to make an enlarged hole that accommodates the flat base of the bolt?
3 Answers
Here's a trick I always use: first, drill a small pilot hole with a 1/16" bit. Then create your larger recess hole using that pilot as a guide. Once deep enough, use the pilot hole to drill the through-hole. This keeps everything nicely centered! Forstner bits are the way to go over spade bits for this.
Such a great suggestion! using a pilot helps prevent tear-out, especially when you're drilling from both sides. Totally agree that Forstner bits give the cleanest results.
You should definitely use a Forstner bit for this! Get one that's large enough for the socket you'll use to tighten the bolt. Just remember to double-check the fit because you don't want it too snug to work with once you've got the bolt in there!
Don't forget to account for the socket! I made the mistake once of making the recess too small; the tool didn’t fit over the bolt head. Learn from my error!
Are Forstner bits okay to use in a regular drill? I thought they were just for drill presses. Just want to make sure before I buy one.
Start with a counterbore using a Forstner or spade bit, then drill your through hole afterward. If you're going from the back, a small pilot hole from the front can help line things up perfectly!
Exactly, counterbores are what you're looking for. Just a heads up: a counterbore has straight sides while a countersink tapers at an angle.
This method is foolproof! The guide hole helps so much, and using the Forstner bit helps minimize any splintering.