Tortoiseshell 51-Piece Metric Index Drill Bit Set, 1.0-6.0 mm, HSS with TiN Coating

Most bits are 0.03mm under size which is good enough for me. Few bits are 0.05mm under sized.Because of the invisible embargo on metrics in the US (last country on earth with Canada not metric in every day life), I am already happy that I could purchase metric drill bits.I got a second 3.4 instead of the 3.3. The seller is sending me a 3.3 bit right away.

I’ll admit that I wasn’t expecting too much in the way of quality with these drill bits; the price was very low for a full set like this. But my expectations were proved wrong. These are excellent drill bits and extremely precise. I use them mainly for musical instrument making on wooden instruments, but they seem to work just fine will aluminum and steel. Highly recommended!

Fairly sharp points and cut well with the right feed, speed and lube. I’m not sure how long these will last drilling a bunch of hard steel. They will probably last a long time drinking softer materials like aluminum, plastic, wood, etc.

Everything about this kit is smack dead average. The box is a little rattily, awkward to open and the way the bits are placed is not bad but hard to see the numbers. The bits themselves are not the correct size. As others pointed out, if you're looking for precision this is not the right place. For example, my 4.0mm is actually 3.941mm (measured with a certified Mitutoyo 293-185-30 Quantumike Micrometer). Also, two of the bits I got already came with chipped tips. I'm giving this 3 stars instead of 1 since they're actually super cheap (<$2 each) and I can always measure for which one will get me close enough and then I'll just use reamers or boring tooling to get me to final dimension.

All undersized between .05-.1mm. Will work good enough for what I'm using it for but way overpriced for what you get

Good quality and sharp.

This is a great set of Metric bits!

The metal case is solid with no opening or closing problems. Bits can be a bit rough to get out as they are packed in there pretty close. Bits came coated in light oil. The bits are sharp. This is a short term review so cannot verify how long they will stay sharp.Here are my measurements using Mitutoyo Absolute Scale Digital Caliper. Bit shanks cleaned before testing. Caliper jaws wiped down before each bit was tested.All in metric-1st row stated size, 2nd row actual size.m1.0-.991.1-1.081.2-1.2 *1.3-1.281.4-1.391.5-1.491.6-1.591.7-1.691.8-1.781.9-1.9 *2.0-1.982.1-2.052.2-2.182.3-2.282.4-2.352.5-2.492.6-2.562.7-2.692.8-2.762.9-2.953.0-2.983.1-3.073.2-3.173.3-3.273.4-3.353.5-3.463.6-3.553.7-3.673.8-3.763.9-3.874.0-3.964.1-4.064.2-4.164.3-4.264.4-4.364.5-4.454.6-4.584.7-4.674.8-4.754.9-4.855.0-4.955.1-5.075.2-5.165.3-5.265.4-5.355.5-5.445.6-5.575.7-5.645.8-5.775.9-5.856.0-5.93ymmvM0.05=0.0019685"You decide if there accurate enough for you. If your a clockmaker, well, erm, probably not a good fit.Hope this helps, more of a time sink testing these than planned..