The day I realized I was over-tightening helicoils on old Canon bodies

About two years ago I was working on a Canon AE-1 Program, installing a helicoil in the tripod mount hole. I had always tightened them down as hard as I could, thinking that was the proper way to secure them. But after the fifth or sixth one, the insert started spinning in the hole instead of grabbing. I was frustrated and asked a retired repair guy named Bill at a shop in Portland about it. He told me helicoils only need to be snugged down, not cranked on, because the thread locker does the real holding. I had been snapping the tangs off and ruining aluminum threads for years without knowing. Has anyone else figured out a trick like this that took them way too long to learn?

2 comments

2 Comments

riverp371mo ago

Ha, @the_dylan is totally right, I used to crank them like bolts but now I know snug is way smarter.

the_dylan1mo ago

Funny thing is, the torque spec for those helicoils is actually lower than most people think. Bill probably saved you from a stripped mount and a whole new bottom plate.