Cobalt Drill Bit Set 1.5mm - 10pcs, M35 Twist Drill Bits Straight Shank, 1.5mm High Speed Steel Drill Bits for Drilling in Hard Metal, Stainless Steel, Cast Iron

This set is a great value for your money . The storage case is very functional and markings are easy to read. The 5% cobalt content makes them very durable and are very sharp. I have drill metals and plastics so great drill ability. Great buy if you are into 3D2A projects.

very nice product

Some claim these are not solid cobalt...maybe a coating...I did not really test these out but my intuitive hunch says maybe these are on the cheaper end ... if these don't end up lasting more than 1 use. ( but I don't really know ). Just wondering what the amazon procedure is to test actual claims. 5% this 8% that.

Bits work great. Mostly used these to drill holes in plastic parts, which is relatively easy. They are definitely sharp out the box and left very clean holes. My only complaint is the box. Mine came with the black holder in pieces. Not sure how it got broken inside of the clear plastic box. I'm not interested in replacing when all it does is store it, just a slight annoyance.

solid drill bits.

Sharp

Kept lubricated, cut through 1/4” thick steel post for 8 holes, all with only 1 bit

Ad has will drill Rockwell hardness 67. I was trying to drill the handle end of a knife and it did not work. The highest hardness of the knife steel can be in this case was Rockwell hardness of 62. That means the drill bit should have worked. But it did not. The good news is the tip of the drill bit only got dull, and it did not break. However, the drill bit set it is a good value for the price. Note I could not effectively centerpunch the steel. If you can't center punch the steel that could be a good indication you cannot drill it with this set.

I made my mounting rack for my solar panels out of used steal pipe, and I had to drill quite a few holes for mounting these panels. The piping was quite hard and I bought five drill bits, so as to make sure I wouldn't run out. To my surprise the drill bits held up really well and I was able to drill all the holes with just one bit. I did pre-drill the holes with a center drill, but that was all I used, and of course some lubricant. I never thought that I could drill these many holes without wearing out the drill bit. Quite amazing.

A hardened piece of steel that broke several conventional bits did not stop these drills. Amazing difference from normal drill bits. Use caution; they will snap if driven too hard / fast. Use lubricant and go slow...they work very well.

Wanted,to have these bits, last longer

Buen producto.

Pense que iba a traer el estuche que tiene en la foto pero lo importante son la brocas y si cumplen con mis necesidades