1/8" Solid Carbide Jobber Drill Bits with Straight Shank and 118° Point Angle, Made from Tungsten Carbide Material,2-Pieces

Knowing these bits are very brittle, I used my metal lathe to drill into the end of a 5/8" diameter (304) stainless steel shaft. The holes needed to be 3/4" deep, have over 24 holes to drill, nonetheless I took my time and ran the lathe at a slow rpm. Began with a #1 HSS center drill to get the hole started with cutting oil. Switched to the first Carbide Bit and it worked great. Did 3 holes this way, each time adding cutting oil, retracting the bit to clear the chips after every 1/32" of drilling. On my 4th job, upon retracting the bit for the final time, the bit broke off inside the hole; Disappointed, I shut off the machine and called it a day. I believe the drill flutes got clogged by the oily chips and snagged the bit. Used the second bit today, same project, and figured out that for deep holes, the bit needs to be fully retracted to clear the chips before continuing the hole. Haven't tried it without cutting oil. Thanks for reading this far. I recommend these bits, just need to treat them with absolute care. Not sure if the broken bit is returnable. Good luck on your project! Aloha!

Bought this for drilling out bolt extractor that someone else broke off in a hole. It looks like a very high quality bit and I anticipate using it in my drill press since tungsten is very brittle and will break off with any side load. My only concern is that these bits don't have any flat spots on the shank for the chuck. These are so hard that the jaws of the chuck are going to bite at all. Maybe that's not and issue since I've yet to try it out. Update: well worth the money! I used it to drill through 2 hardened 12 mm bolts in a rear differential. It took only about 2 minutes to drill about 3/4" into the bolt to insert an extractor and easily backed out the broken bolt. I was worried about using these with a hand drill because tungsten is very brittle and any side load could break it off. It's so sharp that it cuts quickly and evenly at high speed with no lubricant. A regular hss bit requires low speed and lubricant to keep the bit cool and help it cut. Carbide isn't affected by heat like hss and according to machinists you typically don't use lubricant for cutting. I'm now going to by more sizes to have a full set. I highly recommend these bits and this seller has great prices. The bits come in a little plastic hard case to protect the bit. I keep them in their individual cases because I have them in my service truck and subject to lots of vibration and moisture.

I needed o cut through a broken tap that was stuck in a bronze casting, and I couldnt think of anything better. I bought this drill bit and it did the job. As tough as the steel was in that tap, this bit was tougher. It save me for further grief. Next time it happens,( and I hope it never does), Ill order another Tungsten carbide drill bit from LU&MN

Decent product

it worked cut through the hardened steel but very easy to break, especially when you go deep.

They have b ot broken yet. Slow drill speed is always wise with carbide cutting tools

Works great, made short work of cold forged steel.

Very good product. Have broken several bits before I purchased this. It cut thru perfectly and without too much effort.

I needed to drill some holes into carbon fibre tubing and I knew I needed a very sharp and uncoded drillbit for this application. Even though I drilled by hand, it went through like a hot knife through butter. Zero effort. The price point on this was more than fair and the finish and the packaging are all good.

Mèches Ultra résistantes . Recommande fortement.

Works good ! Would buy it again !

I can't give this product enough praise. It is A full TRUE TUNGSTEN CARBIDE. Not the crappy carbide tipped bits! & The only store you can buy just 1 from on Amazon it seems. My rear valve cover bolt snapped while changing the gasket, and then the cobalt extractor bit decided to break while trying to get it out. Was stuck inside real good, nothing i tried worked This drilled through it like a champ, got me out of a really tough spot. Thank you again

Enfin un foret de qualitée qui ne m'a pas fait perdre mon temp et mon argent.Percage dans un acier très dur sans problème.