cutting gears

[Sunset Machine]

(07-20-2012, 09:02 AM)dallen Wrote: I have a question about your chart, it says that the number four cutter cuts from 26 to 34 teeth, but the cutter that I ordered is a number 4 and its marked 21 to 25 curious as to which is right or do different makers make the cutters differently.

Machinery's Handbook says #4 is for 26-34 teeth. Under a section on checking gears, it also says that there should be .387" across 3 teeth for a 20DP 25 tooth gear cut with no clearance, and mumbles something about arc thickness calculations for working any clearance in. The gear looks good, how does it measure up?