20 Best Thread Repair Kit (2022 Updated)

Bought this earler this week. Drilled to specified size and tapped without problem. Inserted coil as recommended. Could not screw in new bolt. Double checked bolt size and tapping info, removed coil, inserted another.

Still no luck, bolt would start but jammed up on first thread. Inspected bolts used for correct size and noticed that the coil was cutting into the first thread thereby preventing insertion. This was the case with both inserts.

Gave up and tapped hole to oversize and installed new oversize bolt. Will be returning kit when I have time to visit store.

I got the required 29/64 drill bit at the provided tap didn’t cut into a cast iron engine block, despite my best efforts. Drilled the hole at next size hole and finally got the tap to bite, but the helicoil didn’t grab.

Didn’t work with head bolt holes on SBC iron block. Helicoil didn’t grab bolt and allow torque. May work fine on other substrates.

Used to repair stripped thread in an engine block. The spring is flimsy and impossible to put in the way they recommend. If repairing any thread where the bottom is longer than the spring, just bore the whole thing and put two in.

The springs hold great but are a pain to put in and shouldn’t be used to repair just a small section of the bolt hole, as it will not allow the bolt to go farther down than the end of the thread.

The tap cut thread in the steel motor block like going thru butter. The insert tool grips and screws in the insert easily. The insert provides new and accurate threads for the bolt. Does exactly what its supposed too.

This tool did exactly what I needed. Fixed a stripped drain plug hole on a transmission. I did have to cut the coil a little shorter so that it wouldn’t be hanging out so much inside the transmission pan.

Worked great. After 2 months, the pan is still dry. No fluid weeping through.

So while removing the head bolts to replace the head gasket 3 of the head bolts snapped flush with the block so I had to drill them out (I tried using an extracto didn’t work) and these Heli-Coils are life savers for these kind of make or break situations (drill bit not included) drilled out the hole according to the specs provided in the instructions and tapped and installed the Heli-Coil and yes I was nervous while I was torquing down the head bolts to the vehicles specs I was so afraid that the Heli-Coils were gonna give under the torque of 60lbft and they held nicely.

Been driving it for almost a month with no issues. I recommend this product.

While this is a great thread restoration kit with most of the tools you’ll ever need to clean up threads, I am very disappointed in the seller’s pricing. I purchased this kit over two months ago for $85, and now it’s priced at $63; over $20.

00 less! The rethreading kit has been great so far and I am glad to have it on hand. It is a much safer alternative than using tap/die kits and it helps prevent further thread damage. Removed two stars for the obvious price gouging.

The kit really isn’t worth $85 and it’s a shame i was stung!.

The Lang Tools 971 – Thread Restorer Set is a quality kit at a very reasonable price. It comes in a plastic case with tools sizes labeled inside. I used this kit to chase and restore the threads on both male and female threads, and it works fantastic.

Be sure to clean the threads and use oil before chasing/restoring.

In full disclosure, I have not yet used this kit. However, I am pleased that these are made the USA and the components appear to be of very good quality. Giving it 4 Stars since I have not yet used the kit to verify functionality.

This product was a huge life saver! I had two stripped bolt holes on my older durango caliper mount. I thought for sure I would have to replace the entire mechanism to correct the problem, but then ran across a discussion board that mentioned these HeliCoil repair kits.

I gave them a try and they worked great! Very easy process, although the directions were vague. I had to go back to the discussion boards to find out the specifics on what other items I would need. For this kit, you also need a 23/64 drill bit.

I also used one slightly smaller one and then stepped up to the larger bit. The tap that came with this kit was also of a very good quality. Overall, this is a wonderful item and one that I am totally thankful exists.

Used for my 01 Dakota brake caliper pins. Worked perfect, I wish I had known about this product sooner. I had just spent $275 for the same issue on the driver side spindle with the same problem, stripped threads.

If you are thinking about trying it, by all means go for it. I love these things. Mine was a M9x125.

The Helicoil worked great but the job would have gone a lot quicker if they included a good tap. I had to do Two helicoils and by the second One the tap was shot. BTW used plenty of oil and backed off threading frequently to clean the tap.

Includes a quality tap, beautifully engineered installation tool, and a small pile of coils. Does not include the proper drill bit, and for the price I paid, it definitely should. Fail on my part for not thinking of it, and the counter guy apologized for not thinking of it, but the kits should either include the drill bit, or at a minimum, cross-merchandised with them.

Cross-merchandise tap handles too.

m10x1. 25 x 15 fixes a japanese 14mm bolt. I used this on my 1995 honda civic d16y7 timing tensioner bolt. It worked perfectly and I was able to reuse the 14mm bolt. I loctite the helicoil spring inside and wait 24hrs for it to dry before installing the 14mm bolt.

I did not and will not use loctite on the 14mm bolt. I’ve since gone back and removed the bolt to do some work and it came off with no problems. The helicoil works as if I never installed it. I used a 13/32 drill bit to drill out the hole before using this kit to tap and install the helicoil.

I used it in a automotive application and was very impressed. Quality kit and comes with everything you need. Although I wouldnt Recommend using theyre plastic chase handle, go and purchase you a handle from the store and get superior results with this kit.

These helicoil kits are great, especially for power equiptment with aluminum blocks. The threads tend to strip out easily, especially at the mufflers, and these kits save the day. Drill out the damaged threads with the specified drill bit.

Retap the hole with the supplied tap, and insert the helicoil with the supplied tool, and you are set, good as new.

Helicoil is the best working & easiest to use in my experience. I recommend this brand product.

Nice kit, Every thing you need to install the helicoil is there. The tap was sharp, The helicoil was easy to install.

This was an excellent repair method to correct cross threading in the end of my crankshaft for the harmonic balancer bolt. I purchased the corresponding drill and tap through Summit and this combination with the Heli Coil kit made a perfect “garage-repair”.

By taking my time and using extra caution, I was able to avoid the cost and additional effort of removing the crank and taking it to a machine shop for repair.

As everyone who has ever used one, Heli-Coils are lifesavers. Follow the directions, and you’ll be on your way!

Used these bad boys on my 1978 Chevrolet Scottsdales’ crankshaft where the stock bolts snapped after a mighty engine rebuild. Couldn’t handle it. But these heli inserts saved me!

Product appeared to be as described but when I attempted to use it the Tap included in the kit for the 1/4-20 coils was the incorrect size. I discovered this because the kit inventory is on the inside of the lid of the kit which references the exact helicoil tap that should be used for each coil size.

The tap that was included for the 1/4-20 coils was not the correct Helicoil part number and it was actually a different helicoil tap that would only be used for Metric M6 coils and not 1/4-20 inch coils.

After discovering this I called Stanley Tools who are the manufactures of Helicoil to verify my discovery and was told that I was correct and the kit should be returned to the seller for replacement.

The Helicoil Tap called out for in the Kit was Helicoil part# 819-4 and the Tap I received in the kit was Helicoil Part# 570-6. This was the only part in the kit that appeared to not match what the kit inventory stated which unfortunately for me was the size I actually needed.

Pros: Good sturdy storage case. The installation tools are the long steel drivers with square shanks that can be driven with a tap wrench – instead of the cheap plastic “keys” shown in the picture. The twist drills are labeled “Made in the USA”.

Cons: The thread taps are made in China. (Stanley Tools. ).

This is a great thread repair kit for the price. I highly recommend.

Lang makes some of the finest tools out there and this set is no exception. As a heavy truck technician, I use this set nearly everyday to clean up threads of gunk and buildup before reassembly. In heavy trucks, proper fastener torque is critical on many components and dirty threads will affect fastener torque.

These tools assure me that my proper torque is set. They thread quickly and smoothly and make quick work of buildup on threads. The only downside is that the plastic case isn’t too durable. The tools however are.

Lang makes this exact same kit for Snap On but by buying the kit with the Lang name you don’t pay Snap On prices. Same tools, different name. I highly recommend this set.

Chasing the threads (male and female) before re-assembly makes things go back together easily and allows a thread sealant to work properly. These were an. essential part of rebuilding a 72 year old Ford flathead.

Good enough quality since these are only for cleaning or chasing threads, not to cut new ones. They are not suitable for that.

This kit is a must have if you work on anything with bolts!!! A must have for any mechanic

Every once in a while I end up with stripped threads in an aluminum casting. I have always been happy with the results of a Helicoil repair. I have never tested any other alternative. I am very careful when using this repair.

Other people that I know didn’t get the new hole straight or broke the thread tap when making this repair. That could be a bad day!.

I got a riding lawn mower with the home I just purchased, and the exhaust manifold and muffler were just dangling from the cylinder head. One of the exhaust manifold studs was stripped and had to be drilled out, and the other stud had been removed but the threads destroyed by the prior owner forcing a non-matching screw into the hole.

I did some research on alternatives to taking the head off to have it drilled and tapped at a machine shop and found this handy kit. It was super easy. Inscribed on the tap was the drill bit size needed, 21/64″, which I had on hand.

It was easy to drill through the aluminum head, and tapping was straight forward. The tap was extremely sharp, and bit into the aluminum right away. I was nervous that it would go in crooked, but the taper at the tip of the tap helped alleviate my concern.

I cut about a half turn, then backed off slightly, blew compressed air into the hold to force out the shavings, then repeated, until I had made it all the way to the back of the hole. The tap screwed back out relatively easily.

After blowing compressed air into the freshly tapped hole to remove aluminum shavings, the thread insert screwed right in by hand using the included tool. Total time for both holes was about 15 minutes.

My only complaint is that the notch at the end of the thread insert didn’t seem to be “notched” enough for the tang at the end to easily snap free. It took several whacks and eventually reaching back in there with tiny needle nose pliers to finally get it out.

For that reason, I’m knocking off a star. Overall I’d definitely buy another kit if I need them in another size. Huge money saver versus taking the head to a machine shop for re-tapping.

When the threads in your aluminium crankcase on your Harley get stripped out from overuse, it’s kind of scary thinking about having to replace the whole thing as the repair! This Helicoil kit saved my butt! Glad it has extra inserts for the future!.

works just make sure to put no pressure when installing the new thread as they could stretch and become unsuitable for the bolt. i also wish the tool had a couple more inches in length for safety purpose.

(pinch points ).

A Helicoil kit is what it is and it does its job very well if you take care to install the coil correctly. I purchased my first Helicoil kit back in 1969 to repair the threads in an aluminum casting on my Harley Davidson XLCH Sportster.

The new Helicoil kit is to repair the cam bearing cap threads (metric) on the aluminum head of my Toyota pickup truck V-6 engine (1994 vintage). I stripped the threads on my Harley but a previous mechanic stripped the threads on the Toyota.

These have been around forever, nice to find this kit when I needed it. Bolt stripped out in a block as I was doing a timing belt, this saved the day. Had to grind the tip down on the tap because of the shallow hole depth.

Quality product, incredibly handy to have the tap and extra coils to install. Just make sure to get the correct size drill bit and you’ll never have to worry about the threads ever again.

I am a DIY-selfer, but have considerable mechanical experience and knowledge. However, wringing off a bolt on rear hatch strut of my PT Cruiser was a new experience for me. Ordered this kit after reading posts and viewing videos on-line.

Recommend all buyers do this reading/viewing because instructions with kit are very limited. Center-punched bolt end and drilled out the bolt and its captive nut to prescribed size. Used kit tap to re-thread nut.

Used supplied tool to insert Helicoil. Reinstalled strut bolt with ease.

Company shipped product quick, it came as advertised. Would have been better if drill bit came with kit but I had a bit that fit. Used to repair a jeep brake caliper mounting bolt hole that was stripped, worked super good.

found out upper bolt was cross threaded and had to repair it as well. So can vouch for two holes repaired with no damage to tap or install tool. Would definitely buy again.

When re-installing a new timing chain guide on my Nissan 2. 5, the threads pulled out from the aluminum engine block, where the guide mounts. After getting the effected hole low enough to get a drill in, by disconnecting the motor mounts, I was able to drill it out, and install this Heli-coil.

So far it is working well.

this kit worked like a charm when I had to fix a broken trans pan bolt. the process I did to remove the old broken and cross threaded bolt caused a lot of damage to the bolt hole threads. the upper trans pan trans housing is aluminum so this helicoil kit worked very well.

I used the recommended drill bit, 1/4 inch I think, to enlarge the bolt hole. then I very slowly and steadily used the thread tap (I put a small blob of grease in the flutes/end of the tap to lube it and to catch the metal shavings) and worked my way through the hole.

I didn’t have a tap handle so I had to use a socket to hold the tap. there was a bit of resistance in the beginning, so I just went like 1/16 to 1/8th of a turn at a time. when I got to the good threads the tap went through with no resistance.

i unscrewed the tap, and used the helicoil insertion tool to place the helicoil into freshly threaded hole. I didn’t have a holder for this tool either so I had to use a reverse torx/star bit to hold the insertion tool.

it took a few tries to get it started into the hole but when I did, it went in fairly easy. I used blue thread locker on the coil when I inserted it as well as on the final bolt when I inserted that.

all in all, this kit worked perfectly fine and I was able to torque the bolt to spec and it has held in place for a few weeks now. I’m happy with the product.

Somehow a nearly impossible to get to valve cover bolt broke of in my motor’s head. It’s a V6 & one bank is nearly vertical & the other is canted way back against the firewall & the broken bolt was on the head’s firewall side, zero working space.

and to make things interesting, it’s a high strength bolt. A right angle dremel tool adapter & a carbide bit managed to drill a hole in it, but it would not budge for the easy-out. Dremel 4200 Variable Speed High Rotary Tool w/ EZ Change (Certified Refurbished) Dremel 575 Right Angle Attachment for Rotary Tool EnPoint™ Premium Carbide Tip Metal Drill Bit 1/8″ 3.

175mm Shank 2. 5mm Cutter Dia CNC Metal Engraving Boring Bit Amber Beeswax Hand Drilling Router Bit for Copper Steel Mold Plastics PCB SMT A Dremel tungsten carbide cutter Dremel 9901 Tungsten Carbide Cutter took care of the bolt remnants & this Helicoil repair kit created new threads.

After the disasters that preceded this kit, I thought I was doomed to a Joe Btfsplk moment. Li’l Abner: The Complete Dailies and Color Sundays, Vol. 4: 1941-1942 This kit worked! My car isn’t going to the crusher over one broken bolt! The included tap is tapered & it would be nice if they included two taps, a tapered & a bottoming, but my dremel tool Dremel EZ406-02 1 1/2-Inch EZ Lock Rotary Tool Cut-Off Wheel and Mandrel Metal Cutting Starter Kit had no problem shortening the tapered tap into a bottoming.

All 12 included inserts measured 5. 8mm long. I couldn’t find any info on this kit & just went with Helicoil’s reputation. Attached are pictures of the instructions & contents that would have been very helpful in in the decision making process.

I drilled out the old worn threads with a 135° quarter inch drill bit. Using my own tap handle, I used the provided tap to cut new threads into my aluminum head block. (A tap handle is not included with this tool set, but it’s necessary for both steps).

Then i use my tab again to drive the thread insert into tHe tgreads I just cut. The bolt went in and is very snug. It was a little hard to turn in, but worked great. The alternative is just to get the next size up of bolt: 8 mm and use a standard 8 mm tap to just cut bigger threads (after drilling it smooth).

I used this tool to repair a thread in a cast aluminum housing. After drilling out the hole using the recommended (but not supplied drill) I tapped the hole with the supplied tap using some cutting fluid.

The tap cut a clean thread. The insertion tool worked as advertised to install the supplied 6mm coil. I was pleased to find that the coil was made from quality, very hard material and it too worked perfectly.

It worked so well I purchased a 10 pack of OEM 6mm inserts and repaired four other 6mm threads in steel with the same tool.

I would give this product perfect stars, but the only thing is it’s not a bang for your buck. For the price you pay, you get the coil insert tool, threader, and only three coils. At this price, I think this product should include more coils and the proper 1/4 inch drill bid.

But it was a perfect fix for my 03 civic stripped out valve cover bolt.

I used this to repair threads on an aluminum motorcycle cylinder. It was easy to tap and insert the coil. When inserting the bolt it felt like it was cross thread, but it went in and snuged up. Maybe that’s how it feels, I don’t know.

It worked though.

I have had a lot of problems with these Helicoils coming in bent or with the tangs not bent. I have sent pictures to my Sales Rep who sent them on to Helicoil.

The true-blue Heli-Coil inserts. Helped me fix a 60yo Black and Decker drill handle that was stripped out.

Helicoil is a great product for repairing damaged threads on bolts and these are great for spark plugs.

I broke 4 engine block studs, drilled and retapped the threads. Unfortunately, the positioning was not precise enough. The solution was to drill bigger, more accurately and fit helicoil. This kit worked perfectly.

I bought a used Chevy block that had some striped head bolts. The Heli-Coil Inserts were installed with no problems. I checked the torque before assembly and they held steady. I’m confident that they will work on final assembly.

This is a decent sized tap so if you are using in steel make sure the piece is supported or clamped firmly. Used two of these on a steering box. Torqued bolts to 60 lb/ft no problem. Solid connection.

I have a B series Kubota tractor that has an aluminum housing for its hydro-static oil reservoir. Of the three drain plugs, one stripped its threads. The Time-Sert replaced the threads perfectly so that the original bolt could be used again.

Because of the confined space, I purchased a tap guide. This plus a small open end wrench allowed me to precisely tap the hole to receive the insert. So far no oil has leaked from the repaired drain plug.

There are videos out there to help you do the job right.

Drill bit is high speed steel. no match against studs that have been hardened due to multiple heat cycles (attempts to weld nuts to broken studs). Tap and insert driver are high quality. Reamer works well the first few times then either loaded up or dulled.

I used this kit in conjunction with another stud drilling guide (gets holes drilled straight in) and finished the job. Replacing 1998 F150 exhaust manifolds with engine in vehicle is not a job for the faint of heart.

This kit made it happen for me.

Arrived before schedualed, great price, excellent product. I would suggest to anyone purchasing this product to do some research on how to use it. If you have never used this before look it up on YouTube.

Bought this to fix the muffler bolt holes on my Briggs and Stratton 5. 5 hp lawnmower engine. First time I ever used a helicoil kit and it was very easy. I have mowed a few times since the fix and it is holding up great.

Glad I found this versus tying up my mower at a shop for who knows how much money. Took about 30 minutes to fix the 2 bolt holes on the mower, didn’t have to pull the motor, could access on the deck which was a huge time saver.

I used loctite red high temp high strength with the install as a second measure. This was a great low cost complete kit. I had to buy a new 17/64 drill bit to ensure I had sharp bit to do the job with no drama.

Installed it on an aluminum bracket on my trolling motor. It worked and allowed me to continue using my trolling motor which I was unable to find parts to replace . Thanks. Saved the day.

-I used it in a mfr’g shop in a bar of aluminum- it worked well. -I liked that it was FAIRLY complete i. e. had quite a few inserts, the special tap and the drive tool. -I didn’t like the fact that it didn’t come with a drill bit, which would’ve made it a complete kit.

-It was a cheaper solution than buying it from a local industrial supply house. -NOTE! I saw a comment about a broken tap. It is imperative that you drill and tap perpendicular to the workpiece! I had a hand-held drill guide and tap guide, which can be made from any piece of discarded steel.

Otherwise you run the risk of a broken drill or tap.

These were more difficult to use than I expected. Smaller Helicoil’s that I’ve used in the past worked pretty easy. I guess because of the larger size they’re installed a little differently. Attaching the helicoil to the installation tool is not intuitive.

At first you swear that it can’t fit. I wasted 2 coils trying to get it onto the install tool. Very carefully and slowly the helicoil does screw over the threads of the install tool. The tap that came with the kit was good.

Pre-drill the hole as instructed and with extreme diligence tap the hole perfectly straight. Use cutting fluid. Memorize the exact angle the tap enters the hole as this is the exact angle the helicoil tool has to be at to work.

Hold the tool flat and hard against the hole till you have screwed the coil in completely. I dabbed oil on the helicoil to help it install smoothly. Take measure of how far you need the helicoil to insert.

You have one shot at this as if you go too far the threads of the sensor will not grab correctly and you cannot back the helicoil back out. Too short you start over. Once you back the tool off the coil you are done.

You cannot get it back on that tool again. Just take a pair of needle nose pliers and rip the coil out and start over. The kit comes with 6 coils and it was the last coil that finally worked. I felt like I hit the lottery.

The oxygen sensor screwed on perfectly. Disclaimer I was doing all this from under the truck as by the shop estimation book it takes 5. 5 hours to remove the manifold from my truck 2003 Toyota Tundra V8.

This saved me several hundred dollars. Hope this helps.

This kit worked easier than expected as this was my first helicoil job. I am mechanically inclined and had an old bolens large frame tractor I was repairing. It had an old Wisconsin s14d engine that wouldn’t run.

I found that the spark plug hole was stripped and need replacement or repair. I used this kit even though it’s for o2 sensor because it’s the same thread dimensions for oem spark plug. I did not use a drill to open hole since the head is aluminium.

The cutting bit included did fine with some motor oil drizzled on by hand. Then the helicoil went in fine. The repair to cut helicoil literally to about 15-20min including me double checking everything since it was my first on.

The engine has been reassembled since Feb 2015 and is still running strong and fine. The only reason I didn’t give five star was the price. If the cylinder head wasn’t a rare one like this one I would have just bought used cylinder head for cheaper.

I cross threaded an 02 sensor in a brand new, (of course), Y-pipe with 2 Cats for my truck. After trying a thread chaser tap, there simply was not enough material left to bolt up a new 02 sensor. This kit worked very well but was expensive.

Compared to the cost of another Y-pipe W/Cat converters it was cheaper. Since this is for such a specialized use, I guess Helicoil charges whatever they want. But I do have the kit if ever needed again and it comes with several extra coils for future repairs.