Flange width (distance between outer flange edges) varies by height for Australian PFC channel steel, ranging from 45 mm (PFC 75) to 150 mm (PFC 400):
Small PFC sizes: PFC 75 (45 mm flange width), PFC 100 (50 mm flange width)
Medium PFC sizes: PFC 200 (75 mm flange width), PFC 250 (85 mm flange width)
Large PFC sizes: PFC 350 (125 mm flange width), PFC 400 (150 mm flange width)Flange width directly impacts load distribution and lateral stability-wider flanges reduce the risk of lateral-torsional buckling in long-span applications (e.g., warehouse roofs). AS/NZS 3679.1 specifies flange width tolerances: ±0.8 mm for widths ≤60 mm, ±1.0 mm for 61–100 mm, and ±1.5 mm for >100 mm. These tolerances ensure the channel fits correctly with Australian-standard bolts (e.g., AS/NZS 1252) and brackets, preventing load concentration.