I'm sure this has been asked many times, but for the life of me I can not find them anywhere. I need a lefthand thread 9/16x20 helicoil for my crank. I can not find them anywhere. All I've found is 9/16x18 righthand thread.

9/16-20 is not a standard UNF thread size. Do you mean 1/2-20 (available as a left-hand helicoil) or 9/16-18 (not, to my knowledge, available as a left-hand helicoil)?

9/16" x 20 tpi is the thread used for most good quality bike pedals and cranks. The left pedal is left-hand threaded, hence the need for that particular threaded helicoil.

Bike Tools Etc has pedal thread repair kits that include 9/16x20 helicoils, both left and right hand threaded. Look here and scroll down:

https://www.biketoolsetc.com/index.cg...ad%20repair&s=

It's not a standard size but it is the pedal size.

I'm guessing there must be a copy cat company that makes bicycle sized helicoils for this but the actual Helicoil site doesn't have this size at all or any left hand thread kits that I can see.

Thank you very much guys! Now I can fix my old Campy Cranks!

Why buy one if you don't have to? They're not cheap. Checked with your LBS? Or a machine shop?

I personally would like to know when and where you get your heli and if it really does
do a sufficient job with those cranks--- what kind of pedals are you using?

I finally got into the other LBS's since my normal one didn't have them. The one didn't really wanna help. And the other one said they are gonna try to get some in. But its been three weeks already, and I stopped in about a week and a half ago and they still didn't have any. SO it looks like I'm gonna be buying some. The plan is to use my campy cranks w/helicoils and me MKS pedals. I will update with pictures and a ride report when finished. If anyone is interested, I may start doing helicoils by mail