Porosity Level 1.
Pin Point Porosity, not larger than 0.25mm ( 0.01") in any
direction is acceptable providing it is widely distributed. (Not grouped
Random pits, not larger than 0.375mm ( 0.15") in any direction
are allowable providing they are widely distributed. (Not grouped or
connected.) They must be completely surrounded by dense parent metal and
be a minimum of 6mm (0.25") apart.
Frequency of pits must be minimal.