you comment that breaking taps you've broken
MOSTLY 1/4-20.

I mostly build small stuff....
It seems like some tap sizes are more fragile than others....
I don't think I've ever broken a 4-40 or 10-32,
I have broken several 6-32 and 1/4-20's
(About the largest hole I ever tap)

Are some taps sizes more prone to breaking than others?

Paul