Metric M42 8% Cobalt Twist Drill Bits Set for Stainless Steel and Hard Metal (1mm-10mm/19pcs)

These drill bits are genuinely very good quality and have performed extremely well for me when drilling into a wide range of materials, particularly metals (excluding concrete and masonry, as expected). They cut cleanly, feel well made, and have clearly been designed with durability in mind. During normal use, I unfortunately had two bits break. I contacted Stroton more to inform them than to complain, fully expecting at most a replacement for the damaged items. Instead, they responded quickly, asked no awkward questions, and simply requested confirmation of my address so they could send out replacements. To my surprise — and genuine appreciation — they sent out an entire new set, not just the broken pieces. This level of customer care is rare these days and speaks volumes about the company’s integrity and confidence in their products. Mistakes or failures can happen with any tool, but how a company responds is what really matters. Stroton handled this perfectly: polite, efficient, generous, and hassle-free. The replacement is already on its way, and I couldn’t be more impressed. Excellent drill bits, but even better customer service. I wouldn’t hesitate to buy from Stroton again and would happily recommend them to others.

Really good quality drill bits for hard stainless steel. I had been trying to drill stainless steel with normal HSS bits and it wasn’t doing anything. These bits drilled straight through it no issues. The swarf came off in big strands as the drill bits easily machined through the steel. Excellent.

The item was sold at a keen price and delivered in double-quick time. I ordered the Cobalt drill bits because, having read the description, I believed they would be a more resilient bit than the normal HSS type, and would do the job of drilling out the sheared stub of a fixing bolt. However, I used two of the new bits to try and drill a pilot hole in the end of the stub and both of them very quickly blunted and lost their cutting edge, making no impression on the stub (I am unable to say what type of steel the sheared bolt stub was manufactured from). In view of this, and previously having blunted and broken several HSS bits, I was forced to abandon trying to remove the stub and used the Cobalt bits to drill a new hole through the 2mm steel sheeting which was easily achieved. And so, although the Cobalt bits didn't perform as I had hoped, they do appear to be quite a sturdy product and easily able to deal with cutting through reasonable thickness, normal steel, without a problem. As a result of the above, I contacted the seller to request replacement of the two damaged bits under the terms of their warranty. They not only responded immediately but did more than I anticipated, sending me a full new set of drill bits, as well as giving me a full refund on those initially purchased! What more could anyone ask for? If that's not excellent customer service, I don't know what is!! I recommend the company highly.

Good drill bits, took an M10 stainless 316 bolt no issues, as long as you know what to do with a drill! ;)

Had a box for over a year now. One use was on quite a few bits of steel from old power pylons, fairly sturdy stuff, hand held drill due to location. Another use has been on galvanized steel field gates, again hand held drill. Holes are made very quickly compared to other bits I've used, but I am an occasional driller rather than professional. They may be more brittle than standard HSS bits as we had a 6mm snap and a few larger bits chip at the ends. I think more careful use could have avoided this but that's hard to do with a hand held drill in some situations. I contacted the seller about the broken bits and within a few days I had a full replacement set! I am seriously impressed with their customer service and warranty.

Really disappointed, instantly snapped after the smallest amount of pressure whilst trying to drill out a screw. Meant to be 8% cobalt and tough! Not so in my experience.

Very sharp and strong

Brilliant drills through hard metal easy

Testate su acciaio da 5mm forando con la n.4 come pilota e sembra indistruttibile, le altre più grandi le usate solo per allargare il foro. La 4,5 usata come pilota si è spaccata al solo contatto con il pezzo, alcune si sono scheggiate lateralmente, probabilmente difetti di fabbricazione. Ho contattato il fornitore che mi ha subito inviato le punte in sostituzione, solo per questo meriterebbe 10 stelle. Provate su barra in ferro da 5mm e forano come se fosse burro. Consiglio pienamente l'acquisto.

I purchased these bits sometime ok...They are very sharp and cut into any material with ease and some cutting fluid of course!! However I did break a few on a project and dulled 4 bits...I contacted costumer service and within a few days they sent me a complete replacement with no questions asked.... Best companies costumer service I dealt with in forever!! Awesomeness!!

Puedes hacer agujeros con facilidad en metales duros como inox 316

Las compré para inoxidables y se soporta las cargas como todo con el uso prolongado van perdiendo filo pero dura bastante para su precio

Gostei As brocas são muito boas