Gear terminology and teeth calculation formulas easy guide
If the teeth are not machined by tooth cutters, and the teeth profiles are still kept intact, then the 2 gears will get jammed in formula for calculating the minimum teeth number without undercutting is:z min =2ha*/sin 2 αWhen ha*=1, and α=20°,we will have the z min =2*1/(sin20°) 2 ==17(always round down). So, the minimum teeth number for standard gears is 17.