Dimensions of sections
2.1. Masses
The masses per metre have been calculated assuming that the density of steel is 7850 kg/m3.
In all cases, including compound sections, the tabulated masses are for the steel section alone and no allowance has been made for connecting material or fittings.
In all cases, including compound sections, the tabulated masses are for the steel section alone and no allowance has been made for connecting material or fittings.
2.2. Ratios for local buckling
The ratios of the flange outstand to thickness (c f / t f ) and the web depth to thickness (c w / t w ) are given for I, H and channel sections.
c f =  [ b − ( t w + 2 r )] |
for I and H sections |
| c f = [ b − ( t w + 2 r )] | for channels |
| c w = d = [ h − 2 ( t f + r )] | for I, H and channel sections |
2.3. Dimensions for detailing
The dimensions C, N and n have the meanings given in the figures at the heads of the tables and have been calculated according to the formulae below. The formulae for N and C makes allowance for rolling tolerances, whereas the formulae for n makes no such allowance.
UB sections, UC sections and bearing piles
| N = (b − t w) / 2 + 10 mm | (rounded to the nearest 2 mm above) |
| n = (h − d) / 2 | (rounded to the nearest 2 mm above) |
| C = t w / 2 + 2 mm | (rounded to the nearest mm) |
Parallel flange and tapered flange channels
| N = (b − t w) + 6 mm | (rounded to the nearest 2 mm above) |
| n = (h − d) / 2 | (taken to the next higher multiple of 2 mm) |
| C = t w + 2 mm | (rounded up to the nearest mm) |