RHS Rectangular Hollow Sections (cold-finished)

The manufacturing of cold formed structural hollow sections is regulated by
European Standard EN 10219:2006
The Standard applies to cold formed structural hollow sections without subsequent heat treatment.

The tolerances for the external radius (R) of the corner depends on the thickness (t):
t ≤ 6 mm → R = (1,6 x t) to (2,4 x t)
6 < t ≤ 10 mm → R = (2,0 x t) to (3,0 x t)
10 mm < t → R = (2,4 x t) to (3,6 x t)