Our company produces steel ladders with guardrail, which are made of grating treads.
When specifying the steel ladders, pls refer to the national standard construction drawing
87J432. According to whether the nosings are to be used and the methods of mounting
to stringers, stair treads are classified into four types: T1, T2, T3, T4. We suggest that the
dimensions are as follow:
Item |
Recommended maximum stair treads length (mm) |
Bearing bar dimension mm |
25*3 |
25*5 |
32*5 |
Bearing bar's pitch at 30 mm |
550 |
900 |
1300 |
Bearing bar's pitch at 40 mm |
450 |
750 |
1200 |
Item |
Recommended stair treads width (mm) |
T1/T2/T3/T4
Bearing bar pitch at 30mm |
95 |
125 |
155 |
185 |
215 |
245 |
275 |
T1/T2
Bearing bar pitch at 40mm
T3/T4 |
|
125 |
165 |
|
205 |
245 |
285 |
|
115 |
155 |
|
195 |
235 |
275 |
Fixing hole center(mm) |
45 |
75 |
100 |
150 |