Steel Bar Grating Manufacturing Tolerance

All steel gratings are produced in accordance with manufacturing tolerances as set forth by NAAMM. And all dimensions given are maximum permissible tolerances.

Bearing Bar & Cross Rod Tolerances

Cross Rod Spacing and Alignment. Cross rods should not vary more than 1/8 in 12 in either direction from perpendicular alignment with bearing bars.

The tolerance of the cross bar spacing for 5'0" in length is ±1/4".

Cross rod spacing and alignment

Cross rod Position. The top of cross rod should not project more than 1/16" above the top of the bearing bars for standard grating (1/8" for heavy duty) and should not extend more than 1/8" from side of bearing bars.

Cross rod position

Bearing Bar Lean. Bearing bar lean must not exceed a slope of 1-1/4 to 12.

Bearing bar lean

Cross Bar Lean. Cross bar lean must not exceed a slope of 2-1/2 to 12.

Cross bar lean

Panel Tolerance

Longitudinal Bow. Longitudinal bow should be less than 1/200 of the length for standard grating (1/240 for Heavy-Duty).

Longitudinal bow

Transverse Bow. Before banding, the transverse bow should be less than 1/8" per foot of width.

Transverse bow

Overall Dimensions and Squareness

• D = Overall diagonal dimension
• W = Length of cross rods including extensions outside of bearing bars
• L = Length of bearing bars

Overall Dimensions and Squareness