Steel stair tread

steel stair tread 1.bearing bar pitch:30.40.60mm 2.cross bar pitch:50.100mm 3.galvanzied,untreate 4.acoording your drawing Steel  Stair Tread1) Bearing Bar (Load Bar) Specifications (mm): The specification of plain type and serrated type bearing bar is 20 x 3 to 100 x 10; The specification of I-section type is 25 x 5 x 3, 32 x 5 x 3, 38 x 5 x 3, 40 x 5 x 3, 50 x 5 x 3, 50 x 7 x 4, 55 x 7 x 4, 60 x 7 x 4, 65 x 7 x 4, 70 x 7 x 4, 75 x 7 x 4, etc. 2) Bearing Bar Pitch (center to center): 12.5, 15, 25, 30, 30.16, 32.5, 34, 40, 41.25, 45, 50, 60, 60.32, 80, 100 mm etc, also be according to client's requirement and 30, 40, 60mm are recommended, America standard is available <1'' x 3/16'', 1 1/4'' x 3/16'', 1-1/2'' x 3/16'', 1'' x 1/4'', 1-1/4'' x 1/4'', 1 1/2'' x 1/4''(19-w-4) and so on. > 3) Material: Mild Steel (Low Carbon Steel ASTM A36 or Q235) or Stainless Steel 4) Surface Treatment: Untreated, Painting or Hot dip Galvanizing 5) Steel grating standards: A) China: YB/T4001-1998 B) USA: ANSI/NAAMM (MBG531-88) C) UK: BS4592-1987 D) Australia: AS1657-1985 E) Japan: JJS. Stair tread, steel stair tread, step ladder