1/4 Inch Cobalt Drill Bit Set, M35 Jobber Length Twist Drill Bits,Suitable for Drilling in Hard Metal, Stainless Steel, Cast Iron,10 Pieces

It's amazing how high quality cheap stuff can be these days. Probably mostly a result of CNC becoming ubiquitous, but the reason doesn't really matter. 20 years ago, the cheapest China machined items were truly dreadful. Like, drill bits in this relative price range would be easily identified as cheap from across the room. Like the shank ends were commonly not even square. Cut with a hand grinder one by one. Anyway, these are lovely. Absolutely flaw free and absolutely identical to one another. Their uniformity doesn't sound like much to wonder at with mass production, but sadly has been. The tips are sharp and the geometry is dead on. I've only used one, but it drilled the last of 30 holes in 12 gauge 304 as well as the first at 240 rpm, with light oil, and a LOT of pressure on the quill. Awesome.

Très bien merci

Muy bueno, se adapto muy bien al taladro y muestra buena durabilidad. Hicimos un ojal en tarja de acero inoxidable. Vienen dos en su estuche y bolsa cada una

Excelente producto

These bits came really sticky, cleaned them up and was blown away. These are the sharpest, most aggressive cutting bits i've ever used. I used these to bore out some existing 1/2" holes in 1/4" A36 mild steel, the first hole I drilled like I do with Bosch M35s and it immediately grabbed and sucked the bit through in one second what typically would take 15-20 seconds of effort. Because of this, the sides of the flute took some noticeable scuffing but nothing that impacted the cutting ability. Once I developed a lighter touch with these they became amazing bits. Even was able to ream out final fit holes through 2x 1/4" steel plate with 2.75" of plywood in the middle with no problem. If your using these with steel make sure to get some Tap Magic and use judiciously. Then hang on for dear life and try not to let the flutes bite and gouge or you will be hurting. Not 100% sure about long term durability but I drilled 8 holes in the aft mentioned steel plates then reamed them out with the same bit, no signs of dulling yet but the finish did start wearing off. Didn't use the second bit yet. For the price these can't be beat.