Flat Bars FL

AS/NZS 3679.1

Hot-rolled flat bar, used for stiffeners, cleats, base plates, straps and general fabrication. Dimensions, section properties, AS 4100 capacities and free DXF drawings for all 113 sizes.

Hot-rolled flat bar to AS/NZS 3679.1, used for stiffeners, cleats, gusset plates, straps, base and cap plates. The x-axis is taken parallel to the wide face, so Ix is the weak-axis value. Check availability of particular width and thickness combinations with your supplier.

Mass per metre = 0.00785 × b × t kg/m (b and t in mm), so a 100x10FL weighs 7.85 kg/m. Flat bar is rolled to width with rolled edges; wider or thicker pieces are cut from plate.

Dimension notation

Select any section in the table to open its page, with a dimensioned drawing, all section properties, AS 4100 capacities and a free DXF download for your CAD software.

Click a column heading to sort. Grade 300 capacities.

Designation	Mass kg/m	b mm	t mm	A_g mm²	I_x 10⁶mm⁴	Z_x 10³mm³	S_x 10³mm³	I_y 10⁶mm⁴	r_y mm	J 10³mm⁴	φM_sx kNm	φN_s kN
300x25FL	58.9	300	25	7500	0.391	31.2	46.9	56.2	86.6	1480	11.8	1890
300x20FL	47.1	300	20	6000	0.200	20.0	30.0	45.0	86.6	766	7.6	1512
300x16FL	37.7	300	16.0	4800	0.102	12.8	19.2	36.0	86.6	396	5.2	1296
300x12FL	28.3	300	12.0	3600	0.0432	7.20	10.8	27.0	86.6	168	2.9	972
300x10FL	23.6	300	10.0	3000	0.0250	5.00	7.50	22.5	86.6	97.9	2.2	864
300x8FL	18.8	300	8.0	2400	0.0128	3.20	4.80	18.0	86.6	50.3	1.4	691
300x6FL	14.1	300	6.0	1800	0.00540	1.80	2.70	13.5	86.6	21.3	0.8	518
250x25FL	49.1	250	25	6250	0.326	26.0	39.1	32.6	72.2	1220	9.8	1575
250x20FL	39.2	250	20	5000	0.167	16.7	25.0	26.0	72.2	633	6.3	1260
250x16FL	31.4	250	16.0	4000	0.0853	10.7	16.0	20.8	72.2	328	4.3	1080
250x12FL	23.6	250	12.0	3000	0.0360	6.00	9.00	15.6	72.2	140	2.4	810
250x10FL	19.6	250	10.0	2500	0.0208	4.17	6.25	13.0	72.2	81.2	1.8	720
250x8FL	15.7	250	8.0	2000	0.0107	2.67	4.00	10.4	72.2	41.8	1.2	576
250x6FL	11.8	250	6.0	1500	0.00450	1.50	2.25	7.81	72.2	17.7	0.6	432
200x25FL	39.2	200	25	5000	0.260	20.8	31.2	16.7	57.7	960	7.9	1260
200x20FL	31.4	200	20	4000	0.133	13.3	20.0	13.3	57.7	500	5.0	1008
200x16FL	25.1	200	16.0	3200	0.0683	8.53	12.8	10.7	57.7	259	3.5	864
200x12FL	18.8	200	12.0	2400	0.0288	4.80	7.20	8.00	57.7	111	1.9	648
200x10FL	15.7	200	10.0	2000	0.0167	3.33	5.00	6.67	57.7	64.6	1.4	576
200x8FL	12.6	200	8.0	1600	0.00853	2.13	3.20	5.33	57.7	33.3	0.9	461
200x6FL	9.42	200	6.0	1200	0.00360	1.20	1.80	4.00	57.7	14.1	0.5	346
180x25FL	35.3	180	25	4500	0.234	18.8	28.1	12.2	52.0	855	7.1	1134
180x20FL	28.3	180	20	3600	0.120	12.0	18.0	9.72	52.0	446	4.5	907
180x16FL	22.6	180	16.0	2880	0.0614	7.68	11.5	7.78	52.0	232	3.1	778
180x12FL	17.0	180	12.0	2160	0.0259	4.32	6.48	5.83	52.0	99.3	1.7	583
180x10FL	14.1	180	10.0	1800	0.0150	3.00	4.50	4.86	52.0	57.9	1.3	518
180x6FL	8.48	180	6.0	1080	0.00324	1.08	1.62	2.92	52.0	12.7	0.5	311
180x5FL	7.06	180	5.0	900	0.00187	0.750	1.12	2.43	52.0	7.37	0.3	259
150x50FL	58.9	150	50	7500	1.56	62.5	93.8	14.1	43.3	4938	23.6	1890
150x25FL	29.4	150	25	3750	0.195	15.6	23.4	7.03	43.3	699	5.9	945
150x20FL	23.6	150	20	3000	0.100	10.0	15.0	5.62	43.3	366	3.8	756
150x16FL	18.8	150	16.0	2400	0.0512	6.40	9.60	4.50	43.3	191	2.6	648
150x12FL	14.1	150	12.0	1800	0.0216	3.60	5.40	3.38	43.3	82.0	1.5	486
150x10FL	11.8	150	10.0	1500	0.0125	2.50	3.75	2.81	43.3	47.9	1.1	432
150x8FL	9.42	150	8.0	1200	0.00640	1.60	2.40	2.25	43.3	24.7	0.7	346
150x6FL	7.06	150	6.0	900	0.00270	0.900	1.35	1.69	43.3	10.5	0.4	259
150x5FL	5.89	150	5.0	750	0.00156	0.625	0.938	1.41	43.3	6.12	0.3	216
130x25FL	25.5	130	25	3250	0.169	13.5	20.3	4.58	37.5	595	5.1	819
130x20FL	20.4	130	20	2600	0.0867	8.67	13.0	3.66	37.5	313	3.3	655
130x16FL	16.3	130	16.0	2080	0.0444	5.55	8.32	2.93	37.5	164	2.2	562
130x12FL	12.2	130	12.0	1560	0.0187	3.12	4.68	2.20	37.5	70.5	1.3	421
130x10FL	10.2	130	10.0	1300	0.0108	2.17	3.25	1.83	37.5	41.2	0.9	374
130x8FL	8.16	130	8.0	1040	0.00555	1.39	2.08	1.46	37.5	21.3	0.6	300
130x6FL	6.12	130	6.0	780	0.00234	0.780	1.17	1.10	37.5	9.09	0.3	225
130x5FL	5.10	130	5.0	650	0.00135	0.542	0.812	0.915	37.5	5.29	0.2	187
110x12FL	10.4	110	12.0	1320	0.0158	2.64	3.96	1.33	31.8	59.0	1.1	356
110x10FL	8.63	110	10.0	1100	0.00917	1.83	2.75	1.11	31.8	34.6	0.8	317
110x8FL	6.91	110	8.0	880	0.00469	1.17	1.76	0.887	31.8	17.9	0.5	253
110x6FL	5.18	110	6.0	660	0.00198	0.660	0.990	0.665	31.8	7.65	0.3	190
100x50FL	39.2	100	50	5000	1.04	41.7	62.5	4.17	28.9	2854	15.8	1260
100x25FL	19.6	100	25	2500	0.130	10.4	15.6	2.08	28.9	439	3.9	630
100x20FL	15.7	100	20	2000	0.0667	6.67	10.0	1.67	28.9	233	2.5	504
100x16FL	12.6	100	16.0	1600	0.0341	4.27	6.40	1.33	28.9	123	1.7	432
100x12FL	9.42	100	12.0	1200	0.0144	2.40	3.60	1.00	28.9	53.2	1.0	324
100x10FL	7.85	100	10.0	1000	0.00833	1.67	2.50	0.833	28.9	31.2	0.7	288
100x8FL	6.28	100	8.0	800	0.00427	1.07	1.60	0.667	28.9	16.2	0.5	230
100x6FL	4.71	100	6.0	600	0.00180	0.600	0.900	0.500	28.9	6.93	0.3	173
100x5FL	3.92	100	5.0	500	0.00104	0.417	0.625	0.417	28.9	4.04	0.2	144
90x12FL	8.48	90	12.0	1080	0.0130	2.16	3.24	0.729	26.0	47.5	0.9	292
90x10FL	7.06	90	10.0	900	0.00750	1.50	2.25	0.608	26.0	27.9	0.6	259
90x8FL	5.65	90	8.0	720	0.00384	0.960	1.44	0.486	26.0	14.5	0.4	207
90x6FL	4.24	90	6.0	540	0.00162	0.540	0.810	0.364	26.0	6.21	0.2	156
90x5FL	3.53	90	5.0	450	0.000937	0.375	0.562	0.304	26.0	3.62	0.2	130
75x25FL	14.7	75	25	1875	0.0977	7.81	11.7	0.879	21.7	309	3.0	472
75x20FL	11.8	75	20	1500	0.0500	5.00	7.50	0.703	21.7	166	1.9	378
75x16FL	9.42	75	16.0	1200	0.0256	3.20	4.80	0.562	21.7	88.6	1.3	324
75x12FL	7.06	75	12.0	900	0.0108	1.80	2.70	0.422	21.7	38.8	0.7	243
75x10FL	5.89	75	10.0	750	0.00625	1.25	1.88	0.352	21.7	22.9	0.5	216
75x8FL	4.71	75	8.0	600	0.00320	0.800	1.20	0.281	21.7	11.9	0.3	173
75x6FL	3.53	75	6.0	450	0.00135	0.450	0.675	0.211	21.7	5.13	0.2	130
75x5FL	2.94	75	5.0	375	0.000781	0.312	0.469	0.176	21.7	2.99	0.1	108
65x25FL	12.8	65	25	1625	0.0846	6.77	10.2	0.572	18.8	257	2.6	410
65x20FL	10.2	65	20	1300	0.0433	4.33	6.50	0.458	18.8	140	1.6	328
65x16FL	8.16	65	16.0	1040	0.0222	2.77	4.16	0.366	18.8	75.0	1.1	281
65x12FL	6.12	65	12.0	780	0.00936	1.56	2.34	0.275	18.8	33.1	0.6	211
65x10FL	5.10	65	10.0	650	0.00542	1.08	1.62	0.229	18.8	19.6	0.5	187
65x8FL	4.08	65	8.0	520	0.00277	0.693	1.04	0.183	18.8	10.2	0.3	150
65x6FL	3.06	65	6.0	390	0.00117	0.390	0.585	0.137	18.8	4.41	0.2	112
65x5FL	2.55	65	5.0	325	0.000677	0.271	0.406	0.114	18.8	2.58	0.1	94
65x3FL	1.53	65	3.0	195	0.000146	0.0975	0.146	0.0687	18.8	0.568	0.0	56
50x25FL	9.81	50	25	1250	0.0651	5.21	7.81	0.260	14.4	178	2.0	315
50x20FL	7.85	50	20	1000	0.0333	3.33	5.00	0.208	14.4	99.7	1.3	252
50x16FL	6.28	50	16.0	800	0.0171	2.13	3.20	0.167	14.4	54.5	0.9	216
50x12FL	4.71	50	12.0	600	0.00720	1.20	1.80	0.125	14.4	24.4	0.5	162
50x10FL	3.92	50	10.0	500	0.00417	0.833	1.25	0.104	14.4	14.6	0.4	144
50x8FL	3.14	50	8.0	400	0.00213	0.533	0.800	0.0833	14.4	7.67	0.2	115
50x6FL	2.35	50	6.0	300	0.000900	0.300	0.450	0.0625	14.4	3.33	0.1	86
50x5FL	1.96	50	5.0	250	0.000521	0.208	0.312	0.0521	14.4	1.95	0.1	72
50x3FL	1.18	50	3.0	150	0.000112	0.0750	0.113	0.0312	14.4	0.433	0.0	43
40x20FL	6.28	40	20	800	0.0267	2.67	4.00	0.107	11.5	73.1	1.0	202
40x16FL	5.02	40	16.0	640	0.0137	1.71	2.56	0.0853	11.5	40.9	0.7	173
40x12FL	3.77	40	12.0	480	0.00576	0.960	1.44	0.0640	11.5	18.7	0.4	130
40x10FL	3.14	40	10.0	400	0.00333	0.667	1.00	0.0533	11.5	11.2	0.3	115
40x8FL	2.51	40	8.0	320	0.00171	0.427	0.640	0.0427	11.5	5.97	0.2	92
40x6FL	1.88	40	6.0	240	0.000720	0.240	0.360	0.0320	11.5	2.61	0.1	69
40x5FL	1.57	40	5.0	200	0.000417	0.167	0.250	0.0267	11.5	1.54	0.1	58
40x3FL	0.94	40	3.0	120	0.0000900	0.0600	0.0900	0.0160	11.5	0.343	0.0	35
32x12FL	3.01	32	12.0	384	0.00461	0.768	1.15	0.0328	9.2	14.1	0.3	104
32x10FL	2.51	32	10.0	320	0.00267	0.533	0.800	0.0273	9.2	8.57	0.2	92
32x8FL	2.01	32	8.0	256	0.00137	0.341	0.512	0.0218	9.2	4.60	0.1	74
32x6FL	1.51	32	6.0	192	0.000576	0.192	0.288	0.0164	9.2	2.03	0.1	55
32x5FL	1.26	32	5.0	160	0.000333	0.133	0.200	0.0137	9.2	1.20	0.1	46
32x3FL	0.75	32	3.0	96	0.0000720	0.0480	0.0720	0.00819	9.2	0.271	0.0	28
25x12FL	2.35	25	12.0	300	0.00360	0.600	0.900	0.0156	7.2	10.0	0.2	81
25x10FL	1.96	25	10.0	250	0.00208	0.417	0.625	0.0130	7.2	6.23	0.2	72
25x8FL	1.57	25	8.0	200	0.00107	0.267	0.400	0.0104	7.2	3.41	0.1	58
25x6FL	1.18	25	6.0	150	0.000450	0.150	0.225	0.00781	7.2	1.53	0.1	43
25x5FL	0.98	25	5.0	125	0.000260	0.104	0.156	0.00651	7.2	0.910	0.0	36
25x3FL	0.59	25	3.0	75	0.0000562	0.0375	0.0563	0.00391	7.2	0.208	0.0	22
20x10FL	1.57	20	10.0	200	0.00167	0.333	0.500	0.00667	5.8	4.57	0.1	58
20x6FL	0.94	20	6.0	120	0.000360	0.120	0.180	0.00400	5.8	1.17	0.1	35
20x5FL	0.78	20	5.0	100	0.000208	0.0833	0.125	0.00333	5.8	0.702	0.0	29
20x3FL	0.47	20	3.0	60	0.0000450	0.0300	0.0450	0.00200	5.8	0.163	0.0	17

All FL DXFs (.zip) Table as CSV Compare sections

Frequently asked questions

How much does flat bar weigh?: Mass per metre = 0.00785 × width × thickness (mm). A 100x10FL is 7.85 kg/m; a 50x6FL is 2.36 kg/m.

Relevant Australian Standards

AS/NZS 3679.1:2016 Structural steel – Part 1: Hot-rolled bars and sections
Specifies chemical composition, mechanical properties and tolerances for hot-rolled universal beams and columns, channels, angles, flats and bars in Grades 300 and 350.
AS 4100:2020 Steel structures
The Australian design Standard for steel members and connections. Covers section classification (Section 5), member moment capacity including lateral-torsional buckling (5.6), shear (5.11), axial compression (Section 6), tension (Section 7) and combined actions (Section 8).

See all Australian Standards for structural steel.