Removing Broken Screw Head

[aminks]

Any suggestions on how I can remove this without damaging the bass? Is there a Dremel tool that might work?
Or should I just drill a completely new hole?

 

[Bruce Johnson]

Any suggestions on how I can remove this without damaging the bass? Is there a Dremel tool that might work?
Or should I just drill a completely new hole?

Unfortunately, snapped off strap button screws are a common problem. The normal way to repair them is to use a Core Drill. Basically a small tube with some teeth on the end. You drill down with it, like a drill bit. It surrounds the broken screw and centers on it. When you get down far enough, the broken screw comes loose and comes out in the center of the core drill.

This leaves you with a round hole centered on the original location. Glue in a short piece of wooden dowel, trim the end off flush, drill a new pilot hole, and put the strap button back on with a new (higher grade!) screw.

I have a machine shop, so I make up nice special core drills for myself from steel. Here's one I made up specifically for broken-off #4 pickguard screws. I've used it many times repairing Ampegs. Somewhere around here I also have one just for #6 strap button screws. You get the idea. It's a tube with a couple of teeth on the end that cut when turning clockwise.

You can make up your own quick core drill from a piece of 1/4" OD brass tubing from the hobby store. While you are there, get some 1/4" birch dowel rod to fill the hole.

Use a small triangular file to cut a couple of teeth on the end of the tube, leaning like I've shown above. They don't have to be perfectly shaped, as long as they come to a good cutting edge.

Chuck your core drill in a small variable speed drill. Start it slowly and gently centered on the broken screw stub. It will cut down around the outside of the screw, following it. Withdraw the core drill a couple of times to clear the chips. Soon, when you withdraw it, the broken screw will come out with it.

 

[TomB]

Unfortunately, snapped off strap button screws are a common problem. The normal way to repair them is to use a Core Drill. Basically a small tube with some teeth on the end. You drill down with it, like a drill bit. It surrounds the broken screw and centers on it. When you get down far enough, the broken screw comes loose and comes out in the center of the core drill.

This leaves you with a round hole centered on the original location. Glue in a short piece of wooden dowel, trim the end off flush, drill a new pilot hole, and put the strap button back on with a new (higher grade!) screw.

I have a machine shop, so I make up nice special core drills for myself from steel. Here's one I made up specifically for broken-off #4 pickguard screws. I've used it many times repairing Ampegs. Somewhere around here I also have one just for #6 strap button screws. You get the idea. It's a tube with a couple of teeth on the end that cut when turning clockwise.

View attachment 4271757

You can make up your own quick core drill from a piece of 1/4" OD brass tubing from the hobby store. While you are there, get some 1/4" birch dowel rod to fill the hole.

Use a small triangular file to cut a couple of teeth on the end of the tube, leaning like I've shown above. They don't have to be perfectly shaped, as long as they come to a good cutting edge.

Chuck your core drill in a small variable speed drill. Start it slowly and gently centered on the broken screw stub. It will cut down around the outside of the screw, following it. Withdraw the core drill a couple of times to clear the chips. Soon, when you withdraw it, the broken screw will come out with it.

Nice! Bruce, is that designed to drill clockwise, or counter? Would that matter?

 

[Bruce Johnson]

Nice! Bruce, is that designed to drill clockwise, or counter? Would that matter?

I've always made them to cut clockwise, normal drilling direction. But I don't think it matters. You could make it reverse direction if you wanted to.

 

[TomB]

I only wondered if counter would more easily extract it, working with the threads. If it doesn’t matter though, then either is good. Thx!