McDuffie
04-27-2004, 11:34 PM
How are welder's shade numbers calculated?
Is it a linear progression; where a stack of two shade 2 filters would be equivalent to a shade 4 filter, or does it follow some other mathematical progression?
Is it a linear progression; where a stack of two shade 2 filters would be equivalent to a shade 4 filter, or does it follow some other mathematical progression?