Helicoil

[Forrest]

Hey guys, I'm about to get started trying to repair a stripped Schaller bridge.

I ordered a package of M3x0.50mm helicoils, and I already have a tap/die set (both my cars are older than me, so I do all my own work) and I'm sure I have the right drill bit.

I've never used a helicoil before, though, any tips? What size bit should I be using for the M3 helicoils?

I just tried to search this forum and apparently the new forum's search function is broken, because it came up with 0 hits. If you've already done a writeup, maybe you can point me to your older post.

[TommyD]

I haven't used one that small for anything yet,but the last Helicoil set I used came with a drill bit AND an oversized tap,so basically you are installing an insert that is oversized on the OD,and 3mm x .5p on the inside.

The drill size will depend on the threads on the OUTSIDE of the insert,typically about 75% of the OD,which translates to a 75% depth of thread,typical of tapped holes.

Where exactly are you using these inserts? Back of saddle for string-lock? Fine-tuner ledge? Anywhere else such as the baseplate (for saddle clamp screws),you will probably find the metal is just too thin for an insert to work,your best bet would be to jump up one size on the screw and tap threads for that.

Hope this helps,Tommy D.

[Forrest]

I got them to fix the stripped out saddle clamp holes. I was under the impression from reading some older threads here that that was a common fix for this problem. That's not the case? The base plate for the damaged bridge is 0.1350" thick. Thanks for the help.

[warlok]

I think the audiozone bridge page says it's been done. I'd try it if it was mine. The Schaller baseplate could be thick enough.