National standard YB/T4001-1998 sign

1. The center to center spacing of Bearing bar recommend to use 30mm，40mm,(15mm,35mm)。
2. The center to center spacing of cross bar recommend to use A（100mm）,B（50mm）。
3. bearing bar shape sign : F refers to standard planar flat steel (can be omitted in the sign ), I refers to section I type flat steel; S refers to serrated flat steel; IS refers to I type serrated flat steel .

4. surface treatment state sign : G refers to hot galvanization (can be omitted in the sign ); P refers to painting; U refers to no treatment .