That is kind of a blanket statement. Carbide end mills can be sharpened several times before they are discarded. The size of the end mill is what will determine whether they are economical to have sharpened. I picked up 7 (mostly Garr's) from work today that were chucked because they were ground under the size range that the CNC programs use. They are supposed to be 1.000 to 0.950 in diameter and were a few thousands under minimum. A couple 3 are perfect and the remainder have a small chip on the end or half way up the flutes from being thrown into the scrap box. The ones with a chipped tip will still side mill fine and the ones with a chip in the flute can still mill at least 1 1/2" deep before getting to the chip. For my home shop needs they are great even if the flutes are a touch on the shallow side. I'm working on the tool room guys to put the undersize re-sharpend bits aside instead of chucking them. I'm a cheap scrounge too and stock up on any bit that may be useful down the road.Mr Ron wrote:Carbide end mills are usually considered throw-away's hence the cheap imports. Good HSS bits and end mills can be sharpened many times and since these came from a maintenance department, they are not used in production schedules; use it once or twice and toss it. Once a carbide tip is chipped, it is gone.
Playtoy_18 what kind of mill do you have, and what shank diameters will it hold? I might be able to help you out with a couple carbide and HSS endmills.
Pete
Looks like Harold beat me to it.