Re tap a hole

ldj · Nov 2, 2016

Today I needed to tap threads in a hole. By mistake I picked up a 3/8-20 tap instead of a 3/8-16, I suppose I had it from working on British motorcycles years ago. When I realized finding a bolt like that is hard to find and really didn't want to re drill for a 7/16 I run a 3/8-16 through that 3/8-20. Threads look pretty good and bolt will torque down. Should I leave it this way or drill and tap to 7-16. Not critical, holds bumper on VW Thing. If it failed worst would happen is it might start rattling since there are 8 bolts holding.

Bob Bancroft · Nov 2, 2016

loc-tite

DGinVT · Nov 2, 2016

Leave it the way it is. It will work. If in doubt use some "green" locktite.

timcasbolt · Nov 3, 2016

I'd put a heli-coil in it.

4wdtom · Nov 3, 2016

Make bolt on lathe with any thread you want/need. Easy way, cut threads off of longer bolt and
rethread on lathe to what you want. Everyone needs a lathe, or a friend with one. Then things like
this are not a problem, but interesting.

dr sportster · Nov 3, 2016

You answered your own question " threads look pretty good and bolt will torque down" . I'm thinking the depth of pitch may be less for the 3/8 -20 than the 3/8-16 and not much damgage was done.

charlie wise · Nov 3, 2016

Depends on depth of thread. Deep is better.

used red MN · Nov 5, 2016

I'm voting the same as the doctor. But now you went and made a crossbreed, it should be metric threads, at least all the VWs I have worked on were. Lol.

Re tap a hole

ldj

Well-known Member

Bob Bancroft

Well-known Member

DGinVT

Member

timcasbolt

Well-known Member

4wdtom

Well-known Member

dr sportster

Well-known Member

charlie wise

New User

used red MN

Well-known Member

Similar threads