10Pcs 1.7mm Carbide End Mill Engraving Milling Cutter CNC Router Bits for PCB Machine, 1/8" Shank

Comes in a handy case and seem to work fine

I used these to "mill" a hole on a 3mm broken screw. The screw was sheared at an angle below the surface with no way to use a punch or grinding wheel to level it out for a drill bit. I broke 3 bits, but successfully removed the screw without collateral damage.

They work ok, but i wish they were stronger. I use these to cut tile and cement board and I can cut about about a 8 foot line before it wears down. I think these are for circuit boards, but there are very few bits on the market that are carbide and titanium coated

Great for the price. Seem to be sharp.

Did not work for sign engraving in 2 layer plastic. My setup works great on a V Carve bit but I was trying for something a little more width consistent because some of the plastic sheets having a little bow to them. These Bits are very brittle. Broke one just setting up the machine, my fault but tip snapped by barley touching the plastic while zeroing out the Z. Did not remove material well and clogged up, melting material to second bit. Third, fourth and fifth bit tried different spindle speeds and feeds. Too slow does not melt but cut looks horrible. Once you get the cut looking good the plastic starts to melt, i have air blast setup so it's not the material on the surface i think the gullet is not deep enough for this application and the plastic is to soft for the speed required for a decent cut. I'm guessing these probably work better on harder materials. I will test them in the future on PCB's as that is what they are designed for and update my review. Just didn't want anyone else to buy them for the wrong thing.