1)Bearing bar pitches may be 12.5,15,20,22,25,30,34,40,60,80and 90mm,of which 20,30and 40mm are recommended.
2)Cross bar pitches may be 24,30,38,50,76and 100mm,of which 50 and 100mmare recommended.
3)Sign of the shape of bearing bars:
F-plain style(may be committed in the symbol of steel grating)
S-serrated style
I-I-section style
4)Sign of surface-treatment; G-hot galvanizing ( may be omit-ted in the symbol of the steel grating)