What hole size to drill for self tapping inserts

I have some threaded inserts I’m trying to drill into my board. However I’m not sure what hole size to drill. Should it be the diameter of the insert excluding or including the outer threads?

depends on the insert…but the same as threads usually

1 Like

First test out of the board, the material it is being screwed on makes a huge difference

I tried it with 5/16 hole. Lmk if this looks ok IMG_20190409_184724

how did it feel going in? easy? snug? hard?

It was hard to get in. Had to use an electric driver. It feels decently snug. As in I can’t pull it out when the hex bolt is in. But I’m pretty sure if I screw it our in reverse with the driver it’ll pop out. That ok?

sure yeah…and as long as the wood doesnt split before it finally seats then good! i use a lil glue around the threads so it stays even better…as I plan on using blue loctitie on my screws so they dont back out from vibration… last thing u want is a blue loctite screw un screwing the insert at the same time… thats a PITA


Put 2-3 drops of RED loctite on to a Q-tip and then gently apply the threadlocker to the outside of your insert before setting it into the wood. Let that cure for an hour before trying to really applying any major torque to tightening or loosening the bolts that you will use to secure your enclosure.

The BLUE loctite is for the bolts. The RED loctite goes between the inserts and the board and requires a heatgun to soften to remove.

Can’t I just use epoxy?

Sure you can, but there is zero room for error. Its quite a bit more messy, and accidental over-spill is something you’ll have to risk dealing with… With RED loctite, it’s super easy to work with in small drops (which is all you need) you’ll get a perfect setting that won’t undo, and if you ever reallyyyyy needed to, You’d be able to heat it up and get back to “watery” enough to back out, and clean up any overspill.

This is the threaded insert Bible


i only have e6000 craft glue so thats what i use… can be a lil messy but what isnt when building =)

I just find a drill bit closest to size of the core of the insert. The threads should start where the hole width ends