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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Two Equal Spans » S Section Steel I Beam » S7 × 20
S Section Steel I Beam | Single Span | Two Equal Spans | Three Equal Spans | Four Equal Spans

For a simply supported beam in two equal spans, we compute the displacement at the middle of each span w_mid and the maximum normal stress stress_max occuring at the center support of the beam.
The tabulated data listed in this page are calculated based on the area moment of inertia (Ixx = 42.4 in4) for the S7 × 20 S Section Steel I Beam and the typical Young's modulus (E = 3.046 × 107 psi) of steels. Note that the typical yielding stress Yield of steels can range from 1.015 × 104 to 2.970 × 105 psi. The purpose of this page is to give a rough estimation of the load-bearing capacity of this particular beam, rather than a guideline for designing actual building structures. Please check your local building codes for regulatory requirements.
Note: The weight of the beam itself is not included in the calculation.
L = 3 ft
L = 5 ft
L = 10 ft
L = 15 ft
L = 20 ft
L = 25 ft
L = 30 ft
L = 40 ft
L = 50 ft
L = 60 ft
L = 70 ft
L = 80 ft
   
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 1.13 × 10-5 22.3
30.0 1.69 × 10-5 33.4
40.0 2.26 × 10-5 44.6
50.0 2.82 × 10-5 55.7
60.0 3.39 × 10-5 66.9
70.0 3.95 × 10-5 78.0
80.0 4.52 × 10-5 89.2
90.0 5.08 × 10-5 100
100 5.64 × 10-5 111
200 1.13 × 10-4 223
300 1.69 × 10-4 334
400 2.26 × 10-4 446
500 2.82 × 10-4 557
600 3.39 × 10-4 669
700 3.95 × 10-4 780
800 4.52 × 10-4 892
900 5.08 × 10-4 1000
1000 5.64 × 10-4 1110
2000 0.00113 2230
3000 0.00169 3340
4000 0.00226 4460
5000 0.00282 5570
6000 0.00339 6690
7000 0.00395 7800
8000 0.00452 8920
9000 0.00508 1.00 × 104
1.00 × 104 0.00564 1.11 × 104
2.00 × 104 0.0113 2.23 × 104
3.00 × 104 0.0169 3.34 × 104
4.00 × 104 0.0226 4.46 × 104
5.00 × 104 0.0282 5.57 × 104
6.00 × 104 0.0339 6.69 × 104
7.00 × 104 0.0395 7.80 × 104
8.00 × 104 0.0452 8.92 × 104
9.00 × 104 0.0508 1.00 × 105
1.00 × 105 0.0564 1.11 × 105
2.00 × 105 0.113 2.23 × 105
2.67 × 105 0.150 2.97 × 105
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 8.71 × 10-5 61.9
30.0 1.31 × 10-4 92.9
40.0 1.74 × 10-4 124
50.0 2.18 × 10-4 155
60.0 2.61 × 10-4 186
70.0 3.05 × 10-4 217
80.0 3.48 × 10-4 248
90.0 3.92 × 10-4 279
100 4.36 × 10-4 310
200 8.71 × 10-4 619
300 0.00131 929
400 0.00174 1240
500 0.00218 1550
600 0.00261 1860
700 0.00305 2170
800 0.00348 2480
900 0.00392 2790
1000 0.00436 3100
2000 0.00871 6190
3000 0.0131 9290
4000 0.0174 1.24 × 104
5000 0.0218 1.55 × 104
6000 0.0261 1.86 × 104
7000 0.0305 2.17 × 104
8000 0.0348 2.48 × 104
9000 0.0392 2.79 × 104
1.00 × 104 0.0436 3.10 × 104
2.00 × 104 0.0871 6.19 × 104
3.00 × 104 0.131 9.29 × 104
4.00 × 104 0.174 1.24 × 105
5.00 × 104 0.218 1.55 × 105
6.00 × 104 0.261 1.86 × 105
7.00 × 104 0.305 2.17 × 105
8.00 × 104 0.348 2.48 × 105
9.00 × 104 0.392 2.79 × 105
9.60 × 104 0.418 2.97 × 105
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.00139 248
30.0 0.00209 371
40.0 0.00279 495
50.0 0.00348 619
60.0 0.00418 743
70.0 0.00488 867
80.0 0.00558 991
90.0 0.00627 1110
100 0.00697 1240
200 0.0139 2480
300 0.0209 3710
400 0.0279 4950
500 0.0348 6190
600 0.0418 7430
700 0.0488 8670
800 0.0558 9910
900 0.0627 1.11 × 104
1000 0.0697 1.24 × 104
2000 0.139 2.48 × 104
3000 0.209 3.71 × 104
4000 0.279 4.95 × 104
5000 0.348 6.19 × 104
6000 0.418 7.43 × 104
7000 0.488 8.67 × 104
8000 0.558 9.91 × 104
9000 0.627 1.11 × 105
1.00 × 104 0.697 1.24 × 105
2.00 × 104 1.39 2.48 × 105
2.40 × 104 1.67 2.97 × 105
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.00706 557
30.0 0.0106 836
40.0 0.0141 1110
50.0 0.0176 1390
60.0 0.0212 1670
70.0 0.0247 1950
80.0 0.0282 2230
90.0 0.0318 2510
100 0.0353 2790
200 0.0706 5570
300 0.106 8360
400 0.141 1.11 × 104
500 0.176 1.39 × 104
600 0.212 1.67 × 104
700 0.247 1.95 × 104
800 0.282 2.23 × 104
900 0.318 2.51 × 104
1000 0.353 2.79 × 104
2000 0.706 5.57 × 104
3000 1.06 8.36 × 104
4000 1.41 1.11 × 105
5000 1.76 1.39 × 105
6000 2.12 1.67 × 105
7000 2.47 1.95 × 105
8000 2.82 2.23 × 105
9000 3.18 2.51 × 105
1.00 × 104 3.53 2.79 × 105
1.07 × 104 3.76 2.97 × 105
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.0223 991
30.0 0.0335 1490
40.0 0.0446 1980
50.0 0.0558 2480
60.0 0.0669 2970
70.0 0.0781 3470
80.0 0.0892 3960
90.0 0.100 4460
100 0.112 4950
200 0.223 9910
300 0.335 1.49 × 104
400 0.446 1.98 × 104
500 0.558 2.48 × 104
600 0.669 2.97 × 104
700 0.781 3.47 × 104
800 0.892 3.96 × 104
900 1.00 4.46 × 104
1000 1.12 4.95 × 104
2000 2.23 9.91 × 104
3000 3.35 1.49 × 105
4000 4.46 1.98 × 105
5000 5.58 2.48 × 105
6000 6.69 2.97 × 105
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.0544 1550
30.0 0.0817 2320
40.0 0.109 3100
50.0 0.136 3870
60.0 0.163 4640
70.0 0.191 5420
80.0 0.218 6190
90.0 0.245 6960
100 0.272 7740
200 0.544 1.55 × 104
300 0.817 2.32 × 104
400 1.09 3.10 × 104
500 1.36 3.87 × 104
600 1.63 4.64 × 104
700 1.91 5.42 × 104
800 2.18 6.19 × 104
900 2.45 6.96 × 104
1000 2.72 7.74 × 104
2000 5.44 1.55 × 105
2570 7.00 1.99 × 105
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.113 2230
30.0 0.169 3340
40.0 0.226 4460
50.0 0.282 5570
60.0 0.339 6690
70.0 0.395 7800
80.0 0.452 8920
90.0 0.508 1.00 × 104
100 0.564 1.11 × 104
200 1.13 2.23 × 104
300 1.69 3.34 × 104
400 2.26 4.46 × 104
500 2.82 5.57 × 104
600 3.39 6.69 × 104
700 3.95 7.80 × 104
800 4.52 8.92 × 104
900 5.08 1.00 × 105
1000 5.64 1.11 × 105
1240 7.00 1.38 × 105
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.357 3960
30.0 0.535 5940
40.0 0.714 7920
50.0 0.892 9910
60.0 1.07 1.19 × 104
70.0 1.25 1.39 × 104
80.0 1.43 1.58 × 104
90.0 1.61 1.78 × 104
100 1.78 1.98 × 104
200 3.57 3.96 × 104
300 5.35 5.94 × 104
392 7.00 7.77 × 104
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.871 6190
30.0 1.31 9290
40.0 1.74 1.24 × 104
50.0 2.18 1.55 × 104
60.0 2.61 1.86 × 104
70.0 3.05 2.17 × 104
80.0 3.48 2.48 × 104
90.0 3.92 2.79 × 104
100 4.36 3.10 × 104
161 7.00 4.97 × 104
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 1.81 8920
30.0 2.71 1.34 × 104
40.0 3.61 1.78 × 104
50.0 4.52 2.23 × 104
60.0 5.42 2.67 × 104
70.0 6.32 3.12 × 104
77.5 7.00 3.45 × 104
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 70.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 3.35 1.21 × 104
30.0 5.02 1.82 × 104
40.0 6.69 2.43 × 104
41.8 7.00 2.54 × 104
Steel I Beam: S7 × 20 (S7 inch tall × 20 lbf/ft)
L = 80.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 5.71 1.58 × 104
24.5 7.00 1.94 × 104
Additional Information
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Injection Molding Design Guide

Guide for high quality and cost-effective plastic injection molding.

Essentials of Manufacturing

Information, coverage of important developments and expert commentary in manufacturing.

CNC Machining Design Guide

Optimize your designs, reduce machining time, and lower your costs.

Salary Expectation

8 things to know about the interview question "What's your salary expectation"?

more publications