... 34.8, 35.3, 40, 60, 80……Pitch of cross bars(mm)38.1, 50, 50.8, 70, 75 ... Grating type: flat bar: plain type, plain I type, serrated type, serrated I type; cross bar: round type and ... square twisted type. Square twisted cross bars are mostly used.And ... round cross bars are normally used for ...