Steel PFC Dimensions

PFC (Parallel Flange Channel), also known as a C-section, is a C-shaped structural steel section with parallel (rather than tapered) flange faces, commonly used for purlins, side rails, bracing, lintels, and as a lighter alternative to a Universal Beam or Column where full I-section capacity isn't needed. PFCs are also frequently used in back-to-back pairs, either bolted or welded, to form a built-up section with much greater torsional resistance than a single channel alone — useful since a single PFC has relatively weak torsional stiffness and shouldn't generally be used as a primary beam without adequate lateral restraint.

The chart below gives dimensional and section property information for standard PFC sizes to BS 5950-1:2000. A PFC's designation (e.g. 100x50x10 PFC) states its depth, width, and mass per metre in that order.

The charts below gives the dimensions for Parallel Flange Channel to BS 5950-1:2000.

Dimensions shown are in mm, if you wish to convert to Inches, please use our universal converter.

If you are interested in different sections why not try these?

PARALLEL FLANGE CHANNEL - BS 5950- 1:2000

Section Designation	Mass per Metre	Depth of Section	Width of Section	Thickness		Distance	Root Radius	Depth between Fillets	Ratios for Local Buckling		Second Moment of Area
				Web	Flange				Flange	Web	Axis	Axis
		D	B	t	T	C	r	d	b/T	d/t	x-x	y-y
	kg/m	mm	mm	mm	mm	cm	mm	mm			cm⁴	cm⁴
100 x 50 x 10	10.2	100	50	5	8.5	1.7	9	65	5.88	13	208	32.3
125 x 65 x 15	14.8	125	65	5.5	9.5	2.3	12	82	6.84	14.9	483	80
150 x 75 x 18	17.9	150	75	5.5	10	2.6	12	106	7.5	19.3	861	131
150 x 90 x 24	23.9	150	90	6.5	12	3.3	12	102	7.5	15.7	1160	253
180 x 75 x 20	20.3	180	75	6	10.5	2.4	12	135	7.14	22.5	1370	146
180 x 90 x 26	26.1	180	90	6.5	12.5	3.2	12	131	7.2	20.2	1820	277
200 x 75 x 23	23.4	200	75	6	12.5	2.5	12	151	6	25.2	1960	170
200 x 90 x 30	29.7	200	90	7	14	3.1	12	148	6.43	21.1	2520	314
230 x 75 x 26	25.7	230	75	6.5	12.5	2.3	12	181	6	27.8	2750	181
230 x 90 x 32	32.2	230	90	7.5	14	2.9	12	178	6.43	23.7	3520	334
260 x 75 x 28	27.6	260	75	7	12	2.1	12	212	6.25	30.3	3620	185
260 x 90 x 35	34.8	260	90	8	14	2.7	12	208	6.43	26	4730	353
300 x 100 x 46	45.5	300	100	9	16.5	3.1	15	237	6.06	26.3	8230	568
300 x 90 x 41	41.4	300	90	9	15.5	2.6	15	245	5.81	27.2	7220	404
380 x 100 x 54	54	380	100	9.5	17.5	2.8	15	315	5.71	33.2	15000	643
430 x 100 x 64	64.4	430	100	11	19	2.6	15	362	5.26	32.9	21900	722

Section Designation	Radius of Gyration		Elastic Modulus		Plastic Modulus		Buckling Parameter	Torsional Index	Warping Constant	Torsional Constant	Area of Section
	Axis	Axis	Axis	Axis	Axis	Axis
	x-x	y-y	x-x	y-y	x-x	y-y	u	x	H	J	A
	cm	cm	cm³	cm³	cm³	cm³			dm⁶	cm⁴	cm²
100 x 50 x 10	4	1.58	41.5	9.89	48.9	17.5	0.942	10	0.0005	2.53	13
125 x 65 x 15	5.07	2.06	77.3	18.8	89.9	33.2	0.945	11.1	0.0019	4.72	18.8
150 x 75 x 18	6.15	2.4	115	26.6	132	47.2	0.945	13.1	0.0047	6.1	22.8
150 x 90 x 24	6.18	2.89	155	44.4	179	76.9	0.937	10.8	0.0089	11.8	30.4
180 x 75 x 20	7.27	2.38	152	28.8	176	51.8	0.945	15.3	0.0075	7.34	25.9
180 x 90 x 26	7.4	2.89	202	47.4	232	83.5	0.95	12.8	0.0141	13.3	33.2
200 x 75 x 23	8.11	2.39	196	33.8	227	60.6	0.956	14.7	0.0107	11.1	29.9
200 x 90 x 30	8.16	2.88	253	53.4	291	94.5	0.952	12.9	0.0197	18.3	37.9
230 x 75 x 26	9.17	2.35	239	34.8	278	63.2	0.945	17.3	0.0153	11.8	32.7
230 x 90 x 32	9.27	2.86	306	55	355	98.9	0.949	15.1	0.0279	19.3	41
260 x 75 x 28	10.1	2.3	278	34.4	328	62	0.932	20.5	0.0203	11.7	35.1
260 x 90 x 35	10.3	2.82	356	56.3	425	102	0.943	17.2	0.0813	20.6	44.4
300 x 100 x 46	11.9	3.13	549	81.7	641	148	0.944	17	0.0813	36.8	58
300 x 90 x 41	11.7	2.77	481	63.1	568	114	0.934	18.4	0.0581	28.8	52.7
380 x 100 x 54	14.8	3.06	791	89.2	933	161	0.933	21.2	0.15	45.7	68.7
430 x 100 x 64	16.3	2.97	1020	97.9	1220	176	0.917	22.5	0.219	63	82.1

FREQUENTLY ASKED QUESTIONS

Why are PFCs often used in back-to-back pairs?

A single PFC has an offset shear centre and relatively weak torsional stiffness, making it prone to twisting under load if used alone as a primary beam. Pairing two PFCs back-to-back (welded or bolted, often with spacer plates) creates a built-up section with much better torsional resistance, closer to that of a full I-section.

What's a typical use for a single PFC?

Purlins, side rails, bracing members, and lintels over openings, where the loading is predominantly simple bending rather than torsion, and full lateral restraint is provided by the surrounding structure.

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