Manufacturing Tolerance
Reference standard – BS 4592-1 / ANSI NAAMM MBG531
Gratings
Permissible Tolerances | |
Location | Tolerance (mm) |
Length of grating panel | +0, -5 |
Width of grating panel | +0, -5 |
Depth of bearing bar: | |
Up to and including 25 | +1, -0.5 |
Over 25 up to 50 | +1.5, -0.75 |
Over 50 up to 100 | +2.0, -1.0 |
Over 100 up to 150 | +2.0, -1.5 |
Thickness of bearing bar: | |
up to 10 | ±0.4 |
over 10 up to 15 | ±0.5 |
Note: Tolerance in accordance with BS 4592-1 | |
Manufacturing Tolerances
Location | Tolerance (mm) |
Difference between the length of diagonals | 5 (out of squareness of grating panel) |
Transverse bars in either direction from perpendicular alignment with bearing bars | 1:100 |
Tranverse bar spacing | ±5 per 1 500 length of bearing bars |
Bearing bar lean | 1:10 |
Transverse bow of panel before fastening to supports | 1:100 |
Longitudinal bow of panel before fastening to supports | 1:200 |
Stair Treads
Manufacturing Tolerances
Location | Tolerance (mm) |
| Length of Stair Tread | +0, -3 |
| Width of Stair Tread | ±3 |
