brick grades

Building brick (per ASTM C62)
Grade	Uses
SW	for severe weather
MW	for moderate weather
NW	no weather, brick that will not be exposed to weather.

Face brick (per ASTM C216)
Grade	Uses
FBS	general use
FBX	mechanically perfect
FBA	a grade permitting considerable non-uniformity, to give architects some variety in design

Sand-lime brick
(per ASTM C73)
Grade	Use
SW	severe weather
MW	moderate weather