loctite form-a-thread
 

Loctite® Form-A- Thread® Stripped Thread Repair - Henkel

i'm thinking of using this to repair a stripped front derailleur cable anchor arm. it sets up in minutes and is supposed to allow for 128 ft/lbs of torque. has anyone this experience? does the packaging allow use of the unused portion months down the road (for the next goof up), or is this a one-and-done product? thanks.

Let us know if you like it. I have a steerer with messy threads, and this could be the ticket.

If there is enough meat left run a slightly larger tap through the hole and use a new machine screw with threads matching the tap.

In SOME cases with BIG and LONG threads perhaps. But there are some past forum threads about this stuff where it simply didn't stand up to bicycle needs.

You're also looking at doing this on a thin tab of a hanger that has only a couple of full turn threads. It's simply NOT going to do the job. You'll be far better off to drill and tap it to the next standard size and take care to not over torque it again. Or simply drill out what is left and use a nut on the back side. Or if it's curved like some of the tabs I've seen use a "D" shaped piece cut from some suitable round bar stock and drilled and threaded to act as a nut.

The last thread I saw about this stuff was someone trying to use it for restoring stripped out bottom bracket shell threads. It didn't take a lot to pull the glue away. And in the end that's all it is. Just another epoxy. Good stuff as it goes but not some sort of miracle worker.

^ you may have talked me out of it for this application. i see what you're saying with the low thread count for a front derailleur arm.

with a bb, i don't see how it would work in the first place, because when setting the mixture, it would move outside the shell into the frame tubes when a cup is threaded into it.

it seems the tap approach might serve me best here.

any other opinions on this?

A complete reading of the data sheet will show that the torques quoted are in inch-pounds not foot-pounds and that the suggested applications are very light duty ones. The max torque for a 1/4 inch/6mm fastener is 23 in-lb, which is less that 2 foot-lb, which ain't much.

... = 2.6 Nm.

thanks dsbrantjr
that 128 ft lbs certainly did not seem right

huh. their web page reads ...

"Allows up to 128 ft. lbs. of torque between -65°F to 300°F."

i looked it up too
the 128 ft lbs or 1538 in lbs is for one inch fasteners
not 4 mm fasteners
this can be found on the product info pdf

^ what is the distinction for the layman?

smaller diameter and/or less depth = less material = less torque capacity

I believe this aplies to most situations.

I used it on a titanium screw going into carbon threads.....worked great ! I used it months down the road on my knife -- screws going into the clip and it worked fine.

^ thanks, 2000, for answering that other question about additional use.

For lighter duty use I can see using this stuff or some other epoxy to hold the parts. But consider the use. For example it's pointless to even bring up using Form-A-Thread or similar products to use for a seat post clamp bolt that needs to be torqued into the upper range of the fastener's allowed torque range. Same with something like a stem pinch bolt. These are critical high torque fasteners.

On the other hand it would likely work just fine for a stripped out water bottle thread insert. But in that case you've got a lot more allowance for using a light torque since the bolt is retaining the cage in a far different way and there isn't a big need for high torque.