Metric M42 8% Cobalt Twist Drill Bits for Stainless Steel and Hard Metal(1.5mm-6.5mm/13pcs)

My dad & I were building a soapbox from salvaged metal, which included an old projector post. This metal tube burned out every single drill bit we owned, even if we started with a small pilot hole and worked up in steps.We tried my last bit, a 10mm high cobalt bit (not from this set), which made it through, but it was also a casualty of this insanely hard tube.I purchased these bits, we mentally prepared ourselves to attack this tube the following weekend and...... the thing was like butter, as if it had never presented itself as a problem!We started at our target (8mm) expecting them not to last, and experienced a very minor amount of chipping due to the stepped design, but it doesn't appear to have affected the performance since.When using them properly (ie, with a pilot hole, lubricate the bit, slow and steady) they are utterly flawless.If you can afford them, buy them, you won't need another set of twist bits unless you eat them.

Cobalt tipped to cut through hard metal items. Lubricate often to prevent excessive heat build up and keep drill speed down for same reason. Did the job removing rusted in bolts holding my car handbrake cables in place.

Certainly more expensive then other makes but you generally pay for what you get. These are good quality and they come with a lift time guarantee, so keep the warranty card with it

Excellent product and service.

Design and advice good. Time will tell how good value is

Not used them long enough to comment

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.

Stroton warrenty policy says broken bit will be replaced, The instructions say click on STROTON logo then ASK A QUESTION then ITEM FOR SALE then PRODUCT DETAILS then fill out text box then a bot pops up supposedly helping BUT the SEND MESSAGE does not light up so presumably the bit will NOT be replaced, why say so?