HYMNORQ13-Piece Cobalt Drill Bit Set with Index Case – M35 Grade (5% Cobalt) Steel, 1.5mm to 6.5mm, Dual Twist Flute, 135° Split Point, Ideal for Hard Metals Like Stainless Steel and Cast Iron

At the time I purchased these, I only intended to use them for light duty (drilling into polymer). However, as fate would have it, I had to use them to drill into hardened steel, and much to my surprise, they performed admirably. It was a pleasant surprise (I was expecting "Chinese junk") and I'm very happy with this purchase; especially considering that it's a METRIC set, which is difficult to find (in the USA). I wish the set had a 1mm bit, but oh well. It's just a preference, not anything against the quality of the bits in this set.=============Update 1/16/18=============My rating has changed from 5 stars down to 3. I needed to drill into metal again--actually I wasn't even drilling new holes, but just "chasing" already existing holes to expand them--and neither the 4.5mm or 4.8mm bits would do anything. They just spun around getting hot, without cutting anything. I even tried the 5mm bit, even though that was too big for my purposes, and it also did nothing but spin. Thus, I've used four of the bits (4, 4.5, 4.8, and 5mm), and only one of them did anything. The one that actually worked did its job well; the others are a HUGE disappointment.=============Update 1/25/18=============Kudos to Migiwata customer service (thank you, Bella!). After hearing about my not-so-pleasant experience with these bits, they sent me a second set. Apparently their original supplier had run dry, and they had to use a second, temporary supplier while the original caught up with demand. The first set that I received was from the temporary supplier. The new set is from the original supplier, and the bits seem to be in order in this new set. So how do you tell the difference? By the case (see photos). The set with the blue dot on the case--which is a plastic retainer to keep the case closed--is from the original supplier. Now if you happen to get a set without the blue dot, don't panic. Just because I got a subpar set that slipped through the manufacturer's quality control process doesn't mean that you did, too. Try the bits out first. WORST case is that Migiwata customer service takes care of you like they did me; best case is you don't even have a problem. As for me and my review of this product, I'm a happy camper again and am bumping my rating back up to 5 stars. The bits are great (make sure to use a good cutting lubricant/coolant) and Migiwata customer service is stellar.

I ordered 5 because I was unsure how durable they would be...I was pleasantly surprised! I drilled sooooo many holes building my overland trailer and these 5 bits did their job with the help of a little oil they held up well. Are they the sharpest? No. But I did not break a single one. Just takes a bit of patience.

I bought this for maker projects. The pin vise is very good quality and works well. I understand the issue that some reviewers have complained about the jaws not holding straight, however, I was able to get the drill bits to hold straight and securely with minimal run out. The internal angle of the jaws is probably too large and the jaws are plated, which makes it more difficult to set the bit properly. However, it wasn't actually very difficult for an experienced machinist or toolmaker. I would not have noticed the issue if I hadn't read the other reviews. One nice feature is that there is a space inside the handle that will hold all but the largest size drill bit. As long as the jaws are closed they will not fall out.The drill bits themselves were not so good. Hence the 4 stars instead of five. They are not soft as other reviewers have reported, however, about half of them are not sharpened correctly and will not drill. If you inspect them under magnification, it is easy to see which ones are good. It really isn't practical to try resharpening this size of bit. However, you can get quality drill bits easily, so I didn't take off much. For me, getting a quality pin vise is way more important than the bits.

You never know how good or bad a drill bit is going to be till you buy it and try it. Hymnorq M35 Cobalt drill bits have been the real deal for me. I've purchased multi-packs of larger daimeter and smaller diameter Hymnorq M35 Cobalt bits that have worked just as well as these 4.2mm bits. Hymnorq M35 cobalt bits are reasonably priced, cut fast, and stay sharp (I do try to take care of them regarding matching RPM to bit diameter and keeping cutting oil on the bits as much as possible). As long as I can continue to find this family of drill bits, I'll continue to replenish my toolboxes with them.

good set of smaller metric bits

Here in the USA, Metric drill bits are extremely scarce as most of the country insists upon using an outdated Imperial system of drill bit sizes varying from fractions of an inch (21/64" anybody?) to an inverse numbering system (with a #2 being bigger than a #6)Refreshingly, the entirely decimal Metric system comes to the rescue! This Metric drill bit set is sized from 1.0mm to 10.0mm in 0.5mm increments. a most useful selection. The bits themselves are sharp and drill clean holes but the metal case, or drill index is not especially great.For sharpness, in a recent project I drilled 16 x 5mm holes and 10 x 3mm holes through 6mm thick aluminum. The last holes drilled as quickly and cleanly as the first, so they are at least decently sharp and durable.By the way, for those that absolutely can not get their head around millimeters, the smallest 1.0mm drill bit is this set is close to 3/64" and the largest 10mm drill is close to 25/64", or a bit bigger than 3/8"

Decent bits. They seem like good quality, but for some inexplicable reason the manufacturer put them in a really brittle and flimsy case. While the bits may last, they will wind up scattered in a drawer.

Arrived on time and as described. Works well.