This set of metric drills performs as described. They are very sharp with a nice relief cut back for chip clearing. No trouble encountered doing metal drilling. Center punch your holes and use a lube oil and the bits should last a long time.. Bits are marked for size and show "HSS Co" stamped on shaft. I would definitely purchase these again.

This set of metric drills performs as described. They are very sharp with a nice relief cut back for chip clearing. No trouble encountered doing metal drilling. Center punch your holes and use a lube oil and the bits should last a long time.. Bits are marked for size and show "HSS Co" stamped on shaft. I would definitely purchase these again.

This set of metric drills performs as described. They are very sharp with a nice relief cut back for chip clearing. No trouble encountered doing metal drilling. Center punch your holes and use a lube oil and the bits should last a long time.. Bits are marked for size and show "HSS Co" stamped on shaft. I would definitely purchase these again.

They are delivered coated with some factory sticky oil for corrosion protection. It can be cleaned with some mineral spirits. This is normal for many unfinished metal bits. Do not remove the coating if you are not going to use the drills. The cutting faces are formed correctly and the length is standard. Last ages drilling plastics and wood. These cobalt drill bits should be your last set of drill bits if you learn how to sharpen them. They are very hard and will cut lots of metal before giving up.

They are delivered coated with some factory sticky oil for corrosion protection. It can be cleaned with some mineral spirits. This is normal for many unfinished metal bits. Do not remove the coating if you are not going to use the drills. The cutting faces are formed correctly and the length is standard. Last ages drilling plastics and wood. These cobalt drill bits should be your last set of drill bits if you learn how to sharpen them. They are very hard and will cut lots of metal before giving up.

They are delivered coated with some factory sticky oil for corrosion protection. It can be cleaned with some mineral spirits. This is normal for many unfinished metal bits. Do not remove the coating if you are not going to use the drills. The cutting faces are formed correctly and the length is standard. Last ages drilling plastics and wood. These cobalt drill bits should be your last set of drill bits if you learn how to sharpen them. They are very hard and will cut lots of metal before giving up.