BILITOOLS Thread Repair Kit SAE, 131-Piece HSS Drill Helicoil Repair Kit 1/4" 5/16" 3/8" 7/16" 1/2"

Had a stripped hole in a cylinder head on a Chevy 305 sb. I ordered this set, it arrived the next day. Cleaned everything and inserted the helicoil in 15 min. When I drilled the threads I put a neodymium magnet under the hole I was drilling the metal shavings went right to the magnet. This is a great set, the case is great too !! I cleaned the hole up, got some WD40 sprayed into the hole, put the threader in my drill after marking it with tape to not drill to far in. It is so sharp it went into the metal with ease just like drilling a screw in.

Worked as advertised and it is amazing. Got me out of a jam my ignition coils bolts got cross threaded, and the bolt was spinning, and I needed a new insert, and after I installed the Heli coils, my bolt was able to tighten and torque. I thought I needed a whole new valve cover, but now I can rest easy.

I don’t leave many reviews, but this little thread repair kit did exactly what it’s supposed to do and was a good value. The tap struggled a little bit with cutting thru cast iron, but all is well.

We tapped the head on a 1979 3tc for the valve cover bolt holes, there are 6 x m6x1.0 holes for the whole cover. The drill bit worked, (on aluminum a soft metal) the tap was clean, the drive tool worked as it should. 4 stars because a couple of the helicoils themselves were slightly deformed in the package, it looked like a manufacturing fault, only a couple but a couple were unusable. For the price the kit is great. half the cost and enough extra coils to not stress the bad ones. I would buy again.

Amazing repair kit for the price. Easy to work with Tap does an amazing job cutting thru aluminum in my case. Repaired threads in 4L60 pan bolt threads. Will definitely buy again if needed

I bought these while doing a head gasket on a 2015 Chevy Cruze. The valve cover thread was stripped on the back passenger due to over torquing the head gasket a couple months ago. This thing was super easy. It held the torque needed for it and took about 2 minutes to do. This was my first time doing a helicoil and boy was it easy. Just make sure you have the drill bit for flattening the hole perfectly center and go slow with the thread maker. I used an extendable magnetic pen to get the little piece out you have to break. Overall very happy with this, and definitely going to buy more kits in difference sizes. It came with a lot of helicoils.

i'm almost finished making a custom router table insert from a 3/8" thick aluminum plate. I have what I thought were the hard parts done: mounting bolt holes, the center bit hole and rabbet to hold some plexiglass zero clearance rings, etc. I planned to tap 8 holes for the starter pin locations -- four centered on the outside edge of all four sides about 3/4" from the edge, and four more in line with those 4, but 3/4" from the bit opening at the center of the plate.After breaking 3 of the 8 taps that came in a set from this site, I sent them back for a refund and bought a single-size drill bit and tap set for much less. That tapped the 4 outside edge holes perfectly.Unfortunately, 2 of the inside holes were slightly too big, because 2 broken taps had to be extracted with a punch and hammer. The final 1/4x20 tap was able to complete those 2, but they wound up looser than they should be The 3rd that broke was the 1/4x20 tap, and it remained in the plate. I was unable to pound it loose. My efforts to remove it also caused some minor damage around the hole.I ordered some diamond hole saw "bits" from this site, and managed to remove enough material around the stuck tap to punch it out. Whew!!Oh, the 4th inside hole was tapped okay except it was not perpendicular. The starter pin was at an angle when screwed in. Four out of four holes were messed up to varying degrees.I've never used the helicoil or any other thread repair product, but the reviews looked promising, and the process appeared simple enough.This helicoil kit arrived today, and I proceeded to repair all 4 holes. I first drilled them all while I had the drill bit from this lit in the drill press. I then tapped the holes using the drill press but turning the spindle by hand to hopefully keep the tap perpendicular to the plate.Between tapping each hole, I used a drill-driver on low speed to extract the tap from the plate, then cleaned and installed it into the press again. I used compressed air to clear out the newly tapped hole, and I followed the instructions to insert the helicoil and break off the pin.Installation succeeded without any problems. The helicoil inserts are almost exactly the same depth as the plate, so that's convenient.Now i have four freshly repaired, threaded holes around the bit opening. There's a very small damaged spot next to the one hole I had trouble extracting the 3rd broken tap from. I may try filling it in with the aluminum braising rods i just got for a different repair, but not right away. It's 99% cosmetic as far as i can tell. The starter pin screw works fine in it and sits perfectly perpendicular. That's what matters most.BTW, I was comfortable with the design of this product, because in woodworking, I use a lot of threaded barrel inserts for jigs and such. The Helicoil is basically a metalworking version of that wood-working fastener.i don't often need to repair stripped threads inside a bolt hole. However, the next time i do, i'll know what to use.

This is a really nice kit! Packaging and shipping was great! I’ll definitely purchase more of these thread repair kits as needed.