Flange width- the horizontal distance between outer flange edges- varies by UB series and depth, with ranges from 80 mm (HEA 80) to 420 mm (HEM 1000):
HEA Series: Flange width 80–420 mm (e.g., HEA 100: 100 mm, HEA 300: 300 mm).
HEB Series: Flange width 80–420 mm (e.g., HEB 120: 120 mm, HEB 400: 400 mm) (wider than HEA for the same depth).
HEM Series: Flange width 100–420 mm (e.g., HEM 140: 140 mm, HEM 500: 500 mm) (widest flanges for maximum stability).Flange width directly impacts load distribution and lateral stability- wider flanges reduce the risk of lateral-torsional buckling in long-span beams. EN 10025-2 specifies flange width tolerances: ±0.8 mm for widths ≤100 mm, ±1.0 mm for 101–200 mm, and ±1.5 mm for >200 mm. These tolerances ensure UB steel interfaces correctly with bolts, brackets, and other structural components.