I stumbled onto a solution for one particular scenario with stripped threads. I was tightening the clamp bolt on my derailleur (#6 in the diagram), and it stripped out the hole in the alloy body. I then tortured myself for days, pondering tapping, inserts, drilling, swapping parts, etc., none of which I liked.

Then I happened to measure the depth of the hole, and I found that it would accept a longer bolt, especially when accounting for the thickness of the radius washer and mounting bracket (7, 8). So I hunted through the little drawers at the local hardware store and found one I liked. They had two options for it in stainless alone. It works like a charm; I didn’t even have to tap any more threads into the depths of the hole.

The head doesn’t match the “umbrella” style of the original bolt, but I see I can get one online if I feel like it, now that I’ve proved the concept

It sure is satisfying to stumble upon a dead-simple solution to a problem that looked like it would require time, dollars, and gray hairs!