Let me start by saying these are great aluminum end mills! Anyway, this time I needed a large one and ordered a 3/8". It got lost in the mail first and when I received it I received a very tinny one which is completely useless to me. Update: that's why I got them originally given 2 two stars but even after I returned the bit and got my money back the seller made every effort to contact me and offer to fix the problem.I understand that reviews matter or they are but i never did there was no seller to contact me to correct the mistake that is fantastic customer service in my book !i should also add that i got some 5/16 size bits from this seller for milling aluminum and steel these are great bits they last much longer than any other end mill I have tried in this price range.