6 spline 6 tooth 3/8 ring would make some of these high stepping smaller saws handy. Was impressed with the grunt a 5100 gained by putting a 6 tooth 420 spur on, keep moving, make chips not dust. Simmonds sawmill guide says you want to make chips not dust, if you are making dust...increase power, reduce speed or reduce toothcount. Dust makes you no money.