Type 72 is a stair tread support suitable for most types of stair tread, including timber, open steel, and checker plate. Fixing of the treads is by two bolt holes in each fitting. Warning: If Type 72 fittings are to be used for a permanent application or subjected to high loads, the stair tread support tube which is located at its ends with a single grub screw, should be drilled and pinned to avoid rotational slip. Ø indicates diameter of fixing holes.
