Bending Strength Calculation of Aluminum Pipe and Steel Pipe

Table of Contents

What Is Bending Strength?

Bending strength refers to the maximum stress that a material can withstand when it ruptures or reaches a specified bending moment under a bending load. This stress is the maximum normal stress during bending and is measured in MPa (megapascals). It reflects the material’s ability to resist bending and is used to measure its bending performance.

Circular Tube Bending Strength

Spec. [mm]	D	d	Thickness [mm]	Cross-sectional area [mm²]	Weight St [Kg/M]	Weight Al [Kg/M]	Iz	I*E (Steel)	I*E (Al)
8	8	6.6	0.7	16.05	0.13	0.04	107.92	22231.50	7554.39
	8	6.4	0.8	18.10	0.14	0.05	118.71	24453.63	8309.49
	8	6.2	0.9	20.07	0.16	0.05	128.53	26476.92	8997.01
	8	6	1.0	21.99	0.17	0.06	137.44	28313.60	9621.13
10	10	8.6	0.7	20.45	0.16	0.06	222.36	45806.54	15565.33
	10	8.4	0.8	23.12	0.18	0.06	246.48	50775.25	17253.73
	10	8.2	0.9	25.73	0.20	0.07	268.94	55401.45	18825.74
	10	8	1.0	28.27	0.22	0.08	289.81	59701.25	20286.83
12	12	10.6	0.7	24.85	0.19	0.07	398.16	82020.77	27871.14
	12	10.4	0.8	28.15	0.22	0.08	443.62	91386.35	31053.61
	12	10.2	0.9	31.38	0.24	0.08	486.54	100226.90	34057.69
	12	10	1.0	34.56	0.27	0.09	527.00	108562.44	36890.15
13	13	11.4	0.8	30.66	0.24	0.08	572.92	118021.19	40104.29
14.5	14.5	13.1	0.7	30.35	0.24	0.08	724.29	149203.29	50700.15
	14.5	12.9	0.8	34.43	0.27	0.09	810.57	166977.19	56739.82
	14.5	12.7	0.9	38.45	0.30	0.10	892.93	183943.35	62505.02
	14.5	12.5	1.0	42.41	0.33	0.11	971.49	200126.62	68004.19
15	15	13.6	0.7	31.45	0.25	0.08	805.76	165986.46	56403.17
	15	13.4	0.8	35.69	0.28	0.10	902.38	185891.00	63166.85
	15	13.2	0.9	39.87	0.31	0.11	994.78	204923.98	69634.36
	15	13	1.0	43.98	0.34	0.12	1083.06	223111.19	75814.48
16	16	14.8	0.6	29.03	0.23	0.08	861.85	177541.24	60329.55
	16	14.6	0.7	33.65	0.26	0.09	986.60	203239.23	69061.88
	16	14.4	0.8	38.20	0.30	0.10	1106.32	227902.57	77442.62
	16	14.2	0.9	42.69	0.33	0.12	1221.16	251559.39	85481.35
	16	14	1.0	47.12	0.37	0.13	1331.25	274237.47	93187.49
17.5	17.5	16.3	0.6	31.86	0.25	0.09	1138.72	234577.05	79710.65
	17.5	16.1	0.7	36.95	0.29	0.10	1305.69	268971.53	91398.09
	17.5	15.9	0.8	41.97	0.33	0.11	1466.54	302107.83	102658.00
	17.5	15.7	0.9	46.94	0.37	0.13	1621.44	334017.02	113500.93
	17.5	15.5	1.0	51.84	0.40	0.14	1770.53	364729.77	123937.30
	17.5	15.1	1.2	61.45	0.48	0.17	2051.88	422686.73	143631.41
19	19	17.8	0.6	34.68	0.27	0.09	1469.35	302686.72	102854.71
	19	17.6	0.7	40.24	0.31	0.11	1687.12	347546.88	118098.45
	19	17.4	0.8	45.74	0.36	0.12	1897.59	390903.50	132831.29
	19	17.2	0.9	51.18	0.40	0.14	2100.93	432790.56	147064.75
	19	17	1.0	56.55	0.44	0.15	2297.29	473241.66	160810.27
	19	16.6	1.2	67.10	0.52	0.18	2669.75	549968.35	186882.45
22	22	20.8	0.6	40.34	0.31	0.11	2310.97	476059.17	161767.68
	22	20.6	0.7	46.84	0.37	0.13	2659.29	547813.52	186150.23
	22	20.4	0.8	53.28	0.42	0.14	2997.61	617508.10	209832.85
	22	20.2	0.9	59.66	0.47	0.16	3326.13	685182.71	232829.08
	22	20	1.0	65.97	0.51	0.18	3645.03	750876.76	255152.30
	22	19.6	1.2	78.41	0.61	0.21	4254.75	876478.88	297832.63
25	25	23.8	0.6	45.99	0.36	0.12	3424.86	705521.67	239740.37
	25	23.6	0.7	53.44	0.42	0.14	3947.63	813212.78	276334.44
	25	23.4	0.8	60.82	0.47	0.16	4457.28	918200.51	312009.88
	25	23.2	0.9	68.14	0.53	0.18	4954.03	1020530.49	346782.20
	25	23	1.0	75.40	0.59	0.20	5438.10	1120247.94	380666.78
	25	22.6	1.2	89.72	0.70	0.24	6369.05	1312024.29	445833.50
	25	22	1.5	110.74	0.86	0.30	7675.75	1581203.51	537302.16
	25	21	2.0	144.51	1.13	0.39	9628.20	1983408.36	673973.71
	25	20	2.5	176.71	1.38	0.48	11320.78	2332080.27	792454.46
28	28	26.6	0.7	60.04	0.47	0.16	5596.69	1152918.26	391768.34
	28	26	1.0	84.82	0.66	0.23	7740.10	1594460.35	541806.91
32	32	29	1.5	143.73	1.12	0.39	16753.28	3451175.44	1172729.52

Rectangular Tube Bending Strength

Spec. [mm]	h	b	R	Thickness [mm]	Cross-sectional area [mm²]	Weight St [Kg/M]	Weight Al [Kg/M]	Iz	I*E (Steel)	I*E (Al)
16*8	16	8	1.2	0.6	26.43	0.21	0.07	836.01	172217.85	58520.63
	16	8	1.4	0.7	30.38	0.24	0.08	940.92	193830.13	65864.61
	16	8	1.6	0.8	34.19	0.27	0.09	1036.68	213556.85	72567.86
	16	8	1.8	0.9	37.87	0.30	0.10	1123.54	231449.31	78647.82
	16	8	2	1.0	41.42	0.32	0.11	1201.74	247558.24	84121.73
12*6	12	6	0.8	0.4	13.35	0.10	0.04	240.74	49592.41	16851.79
	12	6	1.2	0.6	19.23	0.15	0.05	328.01	67570.72	22960.92
	12	6
20*10	20	10	1.2	0.6	33.63	0.26	0.09	1703.31	350881.46	119231.56
	20	10	1.4	0.7	38.78	0.30	0.10	1932.19	398030.68	135253.14
	20	10	1.6	0.8	43.79	0.34	0.12	2146.21	442119.96	150234.94
	20	10	1.8	0.9	48.67	0.38	0.13	2345.70	483214.52	164199.11
	20	10	2	1.0	53.42	0.42	0.14	2530.97	521379.03	177167.63
	20	10	2.4	1.2	62.53	0.49	0.17	2860.07	589173.52	200204.59
22*22	22	22	1.2	0.6	50.43	0.39	0.14	3813.36	785552.24	266935.23
	22	22	1.4	0.7	58.38	0.46	0.16	4365.55	899303.29	305588.50
	22	22	1.6	0.8	66.19	0.52	0.18	4894.99	1008367.62	342649.19
	22	22	1.8	0.9	73.87	0.58	0.20	5402.07	1112826.50	378144.93

Flat Elliptical Tube Bending Strength

Spec. [mm]	h	b	d	Thickness [mm]	Cross-sectional area [mm²]	Weight St [Kg/M]	Weight Al [Kg/M]	Iz	I*E (Steel)	I*E (Al)
21.5*11	21.5	11	9.8	0.6	32.20	0.25	0.09	1604.15	330455.20	112290.60
	21.5	11	9.6	0.7	37.35	0.29	0.10	1842.08	379467.97	128945.43
	21.5	11	9.4	0.8	42.44	0.33	0.11	2072.07	426846.07	145044.78
	21.5	11	9.2	0.9	47.46	0.37	0.13	2294.30	472625.27	160600.82
	21.5	11	9	1.0	52.42	0.41	0.14	2508.94	516840.92	175625.56

Elliptical Tube Bending Strength

Spec. [mm]	a	b	Thickness [mm]	Cross-sectional area [mm²]	Weight St [Kg/M]	Weight Al [Kg/M]	Iz	I*E (Steel)	I*E (Al)
16*8	8	4	0.6	21.49	0.17	0.06	526.40	108439.22	36848.28
	8	4	0.7	24.85	0.19	0.07	600.24	123648.56	42016.50
	8	4	0.8	28.15	0.22	0.08	670.42	138106.70	46929.46
	8	4	0.9	31.38	0.24	0.08	737.08	151837.91	51595.41
	8	4	1.0	34.56	0.27	0.09	800.32	164866.07	56022.45