I'm a beginner blade-smith. Having said that, I bought 2 three packs when they had a sale on 32,120,220 grit belts. They were green last year, but these belts chew through metal. Have to be careful with your pressure on the higher grade belts, probably know w/ better smith's. But as a beginner, after making 32 knives averaging 15" blade length and 4 swords, single edged, averaging 30" I am now just needing to reorder. Amazing belts as far as I am concerned!!