Stripped thread

one of my screw holes for the gear shift gate is stripped and the bolt just keeps turning. any advise on how to fix without replacing it?

 

Can you tap it out to the next size and use a larger screw? Or possibly put some epoxy in and tap that out to the current screw size?
BT

 

i was thinking of usinga larger screw... how would the epoxy application work? rub it around the inside, let it dry then screw back in?

 

since that is a non weight bearing part, I'd try using something to create some friction between the screw and the hole. Flat toothpick perhaps, maybe wrapping the screw with plumbers tape etc.

 

didnt think of that.. good idea

 

Clean and fill the hole with a cold weld and then drill and tap that.

 

The thread size on the shifter gate screws is 5mm x 0.8, and the metal "box" that is threaded for these two screws is only about 3mm thick, so there aren't very many threads tapped into the box, potentially easy to strip. Are you sure that the box is stripped, not the screw itself? If you drilled it out and went to 6mm screws, there would be even fewer threads tapped into the box.

I see in my old McMaster-Carr catalog that they DO list a 5mm x 0.8 threaded U-nut, but they show it with an offset of 15.8mm from the center of the threaded hole to the edge of the panel it is attached to. The hole in the box is quite close to the edge of the panel (much closer than 15mm), so you would have to hammer the U-nut flat and then bend it to the necessary offset. It could be done. Or you could take a hacksaw and cut a slice into the box 15.8mm from the center of the hole and install the U-nut from the side instead of front to back. You would probably need longer screws if you used a U-nut.

Or you could just tack weld a 5mm nut onto the box over the stripped hole. I just measured a 5mm nut, it's 3.8mm thick, so it would raise the gate about 4mm to do that.

Lots of ways to tackle this problem.
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yeah, its definitely the box that is stripped. smooth as a baby's butt. the u-nut sounds like the best and most permanent fix. i just wish the u-nut wasnt too long for the panel it will go on. I might resort to rigging it to fit like you said. unless i go to home depot or someplace and try to find something similar. i'll keep everyone updated!

 

Here in this exotic country we have something called thread tape if you translate it direct to English. It is a thin white tape which you wrap arund threads not working anymore, just to increase the diameter of the screw. Plumbers use it aswell when they have a leaking thread.

Try to find it.

//B//

 

Appears you have clear access to the stripped hole. Buy the tools required and install a helicoil. Or find a machine shop that has the tools and have them install the helicoil. Permenant fix, better than new!

 

I was thinking the same thing if there is enough room to do so. http://www.timesert.com/

 

I saw the title of this thread.................saw who posted it.........not nearly as exciting of a thread as I had hoped.

 

haha.. what ever do you mean?!?!

 

Have you considered using insert rivet nuts (rivnuts, nutserts, or the like)?
I have used these before for similar purposes.
http://www.pegasusautoracing.com/group.asp?GroupID=HARDNUTSERT

 

would i be able to unscrew or take it out when i need to or is it permanent like a rivet? sounds like it

 

There are all kinds of devices for "inserting" a nut into the panel, but in this case, the thing is that the panel is only 3mm thick, so there is very little gripping surface. There isn't an insert (i.e. helicoil) in the original panel, it's just tapped. I looked while I was at the local hardware store, and they only had U-nuts down to 6mm thread, not down to 5mm. They had the screws (but in stainless, not chrome) with the proper oval head phillips, in all kinds of lengths. I'm pretty sure my area metric supply store would have the U-nut in 5mm, but you'd still have to adapt it to fit, as I described earlier.

One other thing you COULD do, but it would be kinda elaborate. You could take a piece of scrap metal about 8mm thick, drill and tap a hole in the necessary 5mm x 0.8 thread, and attach this patch piece to the underside of the stripped panel with a couple of pop rivits. It would be totally invisible.

Really, the best thing to do would be to have the old stripped hole welded or brazed up, then redrill and retap the threads.

 

I'm sure this is the same as white teflon tape available here in US at any large hardware store. I use it to help seal pipe threads at home when necessary. It stretches, which helps it seal to the threads as you wrap it on.

 

Another way - Hank Bushes - very common part in the sheet metal industry

http://www.rivetwise.co.uk/productrange/hankminisert.htm
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JB weld can be bought at Home Depot. After it dries it can be tapped.