I use a bench grinder then after that put the blades on a chisel sharpener and it really makes a nice mirror sward like finish and man it is extremely sharp! i sharpened on my 21 and went to mow for a lawn some wooden round sphere was in the way didnt see it so ran it over geuss what? is was in tiny itty bitty pieces. a normal sharpening would just cut the wooden sphere in quarters or big chunks. so from now on im using the chisel belts and need to go down at lowes to get some more they are about 3 to 4 bucks a piece!!