This bolt look retap-able?

[bob206]

I stripped some threads off a hole on my trucks frame. This is 1 of 2 bolt holes used to help secure a steel winch bumper onto the frame. It is M12x1.25, the right side screws in fine but I accidentally threaded at an angle stripping and mangling up the threads on one hole. Now I can't get the bolt in at all. I attached some photos for reference.

I am thinking about a couple things I can do:

1) Use a tapered plug tap in M12x1.25 to clean up the threads and try not to cross thread into the good threads.

2) Drill, tap and use a Heli-coil or Keensert?

3) Drill and tap in a larger M14x1.25 bolt?

 

[readhead]

Can you get to the back? Clean up the threads, use a longer bolt and put a nut on the back.

 

[bob206]

Can you get to the back? Clean up the threads, use a longer bolt and put a nut on the back.

It is fully boxed and unable to get to the back.

 

[Bigbandguy]

I would try cleaning up the threads first and see if you can tighten the bolt to the torque spec (there is one for everything) . If you cannot tighten to that point then my suggestion would be to go with a larger bolt and new threads.

 

[sc00bz]

There looks like there are enough good threads on the back to be ok.

But, if you are worried about it, here are a couple of options that are quick and easy.

If you can't tap it, drill it out and pick up a nutsert from fastenal. If you take this route, don't bother buying the tool to set big nutserts. A bolt, 2 nuts, a regular washer and a star washer makes the tool to collapse the nutsert with 2 wrenches.


They are commonly used for jeep transfer case skid plates, body armor, etc.

Otherwise, cut a slot in the frame to get to the back of it, put the bolt in and crank it down with a nut and weld the nut to the frame. Then you can close the frame back up.

Edit: Another option is to cut a slot in the bottom of the frame big enough to slide a piece of tapped flat stock in and weld it shut effectively making a flag nut.

Sent from my SM-G930V using Tapatalk

 

[bodyguy16]

Tacoma right?

I would use a re-threading tap not to cut them out loose, should be salvageable, you wont know unless u try.

Sent from my SM-G903W using Tapatalk

 

[6PTsocket]

Tacoma right?

I would use a re-threading tap not to cut them out loose, should be salvageable, you wont know unless u try.

Sent from my SM-G903W using Tapatalk

That should always be the first choice when you have lost thread and don't want to lose any more.

Sent from my SM-G900V using Tapatalk

 

[bob206]

I found these off amazon.com. Would these work as a chaser?

https://www.amazon.com/dp/B01JMRZCV8/?tag=atomicindus08-20

 

[matt_i]

I'd try the regular tap, go slow rotating it back and forth by hand to try to get the best alignment with the existing threads. I would try to clean them up, and then tighten the bolt to torque. If that goes well you are ok. If the bolt starts to strip, then I'd go to the next size up.

Many times a threaded insert requires a bigger tapped hole than the next bolt size up.

 

[doge]

I have had good luck with timeserts, but try to clean the threads first since it's easiest

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[RWorth]

I'd try the regular tap, go slow rotating it back and forth by hand to try to get the best alignment with the existing threads. I would try to clean them up, and then tighten the bolt to torque. If that goes well you are ok. If the bolt starts to strip, then I'd go to the next size up.

Many times a threaded insert requires a bigger tapped hole than the next bolt size up.

that chaser he found has a mice line up shaft on the end, helps to start you off straight, I like it.

also if the threads are questionable when you're done, use a stud with locktite instead of a bolt, less apt to strip the threads.

 

[bob206]

Great information fellas! Glad I found this site.

So far I purchased the following.

-tapered plug m12x1.25 tap
-m12x1.25 thread chaser
-heli coil m12x1.25 kit + 31/64 drill bit

I'm going to try to the thread chaser first then the tap. If I royally screw up all the threads I will use the heli kit. It calls for a 31/64 bit which is roughly 12.3mm.

If I do decide not to use the heli kit at all and want to go with the next size up, it would be a m14x1.25 bolt. I'll need a new tap 12.8mm drill bit(per various tap size charts)

 

[bob206]

that chaser he found has a mice line up shaft on the end, helps to start you off straight, I like it.

also if the threads are questionable when you're done, use a stud with locktite instead of a bolt, less apt to strip the threads.

Thanks for this insight. I'm having trouble picturing the stud instead of the bolt. Can you give me an example? Thank you!

 

[slimcake]

heli-coil?

 

[cjcocn]

strap bolt would also work if you can access the bolt hole from the inside.

 

[Orionrising]

A winch mount is not something I would want to be questionable about the bolts on...

Sent from my Moto G (4) using Tapatalk

 

[bob206]

Gentleman,

Used a m12x1.25 plug tap and slowly turned the threading, backing out every other turn. Used some CLP oil I had laying around. Clean up the threads nicely.

Thanks guys!

 

[Ray-CA]

Gentleman,

Used a m12x1.25 plug tap and slowly turned the threading, backing out every other turn. Used some CLP oil I had laying around. Clean up the threads nicely.

Thanks guys!

Glad it worked. I was about to suggest just drilling through the other side and using a longer bolt.

Ray

 

[mlum6969]

nice work! a thread chaser would be my first choice before using a plug tap though..

 

[PelicanPines]

Gentleman,

Used a m12x1.25 plug tap and slowly turned the threading, backing out every other turn. Used some CLP oil I had laying around. Clean up the threads nicely.

Thanks guys!

Awesome... I probably tap or fix threads a few times a week... I have thread repair chaser taps, cutting taps and split dies.

In your case... my first would have been a block of wood held in place with a matching hole to keep the tap square... that technique saved me more than eyeballing it straight. Just a thought for the future.

Kind of agree with a chaser first first tho.