50pcs PCB Drill Bits Set Spiral Flute Carbide 0.3mm-1.2mm for Print Circuit Board Stone Dremel Jewelry CNC Engraving (5PCS Each)

My immediate reaction was the drill bits looked well made and the individual boxes will provide good protection for the drill bits. I wasn't thrilled that the bits are not marked with the size. It was not difficult to make labels to affix to each bit and I have already done so. Doing it took some time but at least I won't have to measure a bit every time I want to use them. I used a digital micrometer to measure each bit. As far as their performance goes they work great. They are very sharp and I have already used them on three types of wood and bamboo, as well as plastic. The bits cut through everything with ease. I even had to drill some holes on sloped surfaces and if you start slowly the bits will not deflect. I think because they are tungsten carbide they are quite stiff and that helps on angled surfaces. However, I am sure most users know that since they are stiff and being quite small diameters you will have best results if used with a drill press. Drilling by hand can be done but the risks of breaking bits is greater Overall I am very pleased and hopefully the bits will stay sharp over time.

They look like nice bits they seem to work well, I have broken 2 of them but I think that is more due to my lack of knowledge in how to operate my cnc machine. I m trying to etch a circuit board for an automation system I built, but what I did was prove that I am not even smart enough to open a box of cnc bits without injuring myself. I tried to open one of the boxes and it was stuck kind of hard, so I forced it open and buried the .4 and .5 bits into my finger, all the way in. I wish I had the cognitive reasoning of a sane person that didn't have two long needles stuck in their fingers and had taken a picture, because it looked like uncle martins antenna from my favorite Martian sticking out of my finger. To make matters worse I kept hearing this high pitched squeal and immediately though ,oh no, I must have accidentally turned on the machine. So instead of pulling out those 2 tiny daggers that thankfully my distal phalange (top finger bone) had to forethought to stop for me, I started looking at the machine to make sure it was off. The noise as it was, happened to be my daughter (20) squealing like a nutter because I was standing there with bits of tools sticking out of my person at odd angles. Worst of all it was my middle finger, the hardest working finger in the universe. I've been married for 23 years, its how we say good morning, its how we pass each other in the hallway so we can at least say we had hallway sex, its how I let my kids my dog and my boss know that they are number one in my life. They were stuck in so good that they even came out of the box still in my finger. So they are sharp, and be careful opening the little boxes.

This set gives you five each of ten different size PCB drill bits for a total of 50 pieces. They have a 1/8" diameter shank and intended to be used with a low torque drill, either manual or motor (e.g., Dremel). These bits are small diameter and will not tolerate bending stresses or high compressive loads without failing. Used with care, they should last sufficiently long to complete a basic PCB project. Don't expect miracles and you will get value for your money.

Love these! Bought them multiple times!

Great for small work.

You get 5 packs that surely seem identical. Broke 4 removing PLA supports, so not even making a hole in solid plastic. On solid plastic, you wont get the drill very deep before it breaks. Wouldn't buy again, even though they're micro drill bits, I expected some to break but 4 in a row with very little pressure seems excessive.

As a scale modeller, I'm always drilling holes in styrene plastic. As with any miniature tool, care must be used to avoid breakage. Some of these drill bits are no larger than a straight pin. Some reviewers fault these tiny bits for breaking. Well, that's gonna happen if you try to muscle them through whatever material you're drilling in. Think finesse when using these. Five sets for something like 10$ is a bargain, even if you do break some of them. Mine work fine. Oh and by the way I use them handheld, not in a pin vise.

Buen producto.

Muy frágiles

５ケース入りだったので購入。当たり前だが，細いドリルは作業中に余計な方向から力が加わったり，落としたりするとすぐに折れる。使ってすぐに折れた。慣れてくるとそれほどでもないが，慎重さは必要。特に０．４ｍｍ以下は折れに注意。それ以上の大きさはずっと使えそうな感じがする。５セットもあるので。

They do the job but as to be expected, the small (er) ones are super easy to break so yeah, the 5 pack is gonna come in REAL handy. It's not the tools fault it's the tool running the tool, I didn't have my drill bit square to the piece i was drilling a couple of times and they break easy. If you're using them square to you work piece and dont change the bits angle once you're in and allow the bit to pull itself through you will be amazing at what they can do

Excellent quality, I would not use the smallest drills in a hand twist drill though, too fine to trust, they will break. Only to be expected at that size. They are best used in a Dremel type drill that is powered. Not too fast a speed and care must be taken as with any drilling job with fine drill bits.

腕時計の金属ベルトを加工する為に購入しました。 穴径を多きする為に使いましたが、案の定１本目は途中で折ってしまいました。 こんな時も５セット有るので、安心して作業を終えることが出来ました。 今回は一番太いドリルを使いましたので、他のサイズは分かりませんが良い商品です。