Parallel flange channel (PFC)
PFC (parallel flange channel) is the hot-rolled C-section steel used for residential lintels. Grade 300, AS/NZS 3679.1, sizes 75 to 380 PFC.
Ask Chalkline about this →A parallel flange channel (PFC) is a hot-rolled structural steel section with a C-shaped profile: a vertical web with two horizontal flanges extending to one side (verified 2026-06-11, InfraBuild product page). The flanges run parallel to each other, unlike older tapered-flange channels. In Australia, PFCs are produced to AS/NZS 3679.1:2016 at Grade 300 (300 MPa minimum yield strength) and designed under AS 4100:2020.
PFCs are not cold-formed steel. They are hot-rolled open sections, which makes them heavier and stiffer than light-gauge framing profiles and puts them under a completely different design standard (AS 4100, not AS/NZS 4600).
Standard sizes
The residential range spans 75 PFC to 380 PFC, with the size number giving the section depth in millimetres. Typical lintel sections (verified 2026-06-11, InfraBuild):
| Size | Mass (kg/m) | Flange width |
|---|---|---|
| 150 PFC | 17.7 | 75 mm |
| 180 PFC | 20.9 | 75 mm |
| 200 PFC | 22.9 | 75 mm |
| 230 PFC | 25.1 | 75 mm |
| 250 PFC | 35.5 | 90 mm |
| 300 PFC | 40.1 | 90 mm |
How PFCs are used as lintels
A single PFC is open to torsion because the web and flanges are on one side only. The standard fix is a back-to-back pair: two PFCs placed with their webs facing each other and bolted or welded together, forming a closed box-like section that resists twist (verified 2026-06-11, Steel Builders). A steel flat plate is often welded to the bottom flanges to give a flush bearing surface and to close the bottom of the section.
150 PFC and 200 PFC pairs handle the majority of residential door and window openings. 250 PFC and 300 PFC pairs are used for wider openings, garage headers, and lintels carrying a second storey. Section size is always the structural engineer’s call under AS 4100.
Also known as: PFC, C-section, channel section.
Category: Materials / Structural steel.
Related
See also
References
- InfraBuild: PFC parallel flange channels product page (verified 2026-06-11)
- Steel Builders: what is PFC? (verified 2026-06-11)
- AS/NZS 3679.1:2016 Structural steel, Standards Australia (verified 2026-06-11)
Last updated: 2026-06-11. Verified: 2026-06-11. Quarterly review for currency.