Debljina mreže- vertikalnog preseka koji povezuje prirubnice- varira u zavisnosti od serije UB i dubine, u rasponu od 4,0 mm (HEA 80) do 25,0 mm (HEM 1000):
HEA serija: Debljina mreže 4,0–20,0 mm (npr. HEA 100: 5,0 mm, HEA 300: 10,5 mm).
HEB Series: Debljina mreže 4,5–22,0 mm (npr. HEB 120: 6,5 mm, HEB 400: 13,5 mm) (deblji od HEA za veći kapacitet smicanja).
HEM Series: Web thickness 5.0–25.0 mm (e.g., HEM 140: 8.0 mm, HEM 500: 18.0 mm) (thickest webs for heavy shear loads).The web's primary role is to resist shear forces (e.g., wind, seismic loads). Thicker webs handle higher shear, making HEM series UB steel suitable for short-span, heavy-load applications (e.g., industrial crane girders). EN 10025-2 specifies web thickness tolerances: ±0.4 mm for thicknesses ≤10 mm, ±0.5 mm for 10.1–20 mm, and ±0.6 mm for >20 mm. Ove tolerancije osiguravaju konzistentan učinak smicanja u serijama.