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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Single Span » 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 a single span, the maximum displacement w_max and the maximum normal stress stress_max occur at the center 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
   
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 2.82 × 10-5 22.3
30.0 4.23 × 10-5 33.4
40.0 5.64 × 10-5 44.6
50.0 7.06 × 10-5 55.7
60.0 8.47 × 10-5 66.9
70.0 9.88 × 10-5 78.0
80.0 1.13 × 10-4 89.2
90.0 1.27 × 10-4 100
100 1.41 × 10-4 111
200 2.82 × 10-4 223
300 4.23 × 10-4 334
400 5.64 × 10-4 446
500 7.06 × 10-4 557
600 8.47 × 10-4 669
700 9.88 × 10-4 780
800 0.00113 892
900 0.00127 1000
1000 0.00141 1110
2000 0.00282 2230
3000 0.00423 3340
4000 0.00564 4460
5000 0.00706 5570
6000 0.00847 6690
7000 0.00988 7800
8000 0.0113 8920
9000 0.0127 1.00 × 104
1.00 × 104 0.0141 1.11 × 104
2.00 × 104 0.0282 2.23 × 104
3.00 × 104 0.0423 3.34 × 104
4.00 × 104 0.0564 4.46 × 104
5.00 × 104 0.0706 5.57 × 104
6.00 × 104 0.0847 6.69 × 104
7.00 × 104 0.0988 7.80 × 104
8.00 × 104 0.113 8.92 × 104
9.00 × 104 0.127 1.00 × 105
1.00 × 105 0.141 1.11 × 105
2.00 × 105 0.282 2.23 × 105
2.67 × 105 0.376 2.97 × 105
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 2.18 × 10-4 61.9
30.0 3.27 × 10-4 92.9
40.0 4.36 × 10-4 124
50.0 5.44 × 10-4 155
60.0 6.53 × 10-4 186
70.0 7.62 × 10-4 217
80.0 8.71 × 10-4 248
90.0 9.80 × 10-4 279
100 0.00109 310
200 0.00218 619
300 0.00327 929
400 0.00436 1240
500 0.00544 1550
600 0.00653 1860
700 0.00762 2170
800 0.00871 2480
900 0.00980 2790
1000 0.0109 3100
2000 0.0218 6190
3000 0.0327 9290
4000 0.0436 1.24 × 104
5000 0.0544 1.55 × 104
6000 0.0653 1.86 × 104
7000 0.0762 2.17 × 104
8000 0.0871 2.48 × 104
9000 0.0980 2.79 × 104
1.00 × 104 0.109 3.10 × 104
2.00 × 104 0.218 6.19 × 104
3.00 × 104 0.327 9.29 × 104
4.00 × 104 0.436 1.24 × 105
5.00 × 104 0.544 1.55 × 105
6.00 × 104 0.653 1.86 × 105
7.00 × 104 0.762 2.17 × 105
8.00 × 104 0.871 2.48 × 105
9.00 × 104 0.980 2.79 × 105
9.60 × 104 1.04 2.97 × 105
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.00348 248
30.0 0.00523 371
40.0 0.00697 495
50.0 0.00871 619
60.0 0.0105 743
70.0 0.0122 867
80.0 0.0139 991
90.0 0.0157 1110
100 0.0174 1240
200 0.0348 2480
300 0.0523 3710
400 0.0697 4950
500 0.0871 6190
600 0.105 7430
700 0.122 8670
800 0.139 9910
900 0.157 1.11 × 104
1000 0.174 1.24 × 104
2000 0.348 2.48 × 104
3000 0.523 3.71 × 104
4000 0.697 4.95 × 104
5000 0.871 6.19 × 104
6000 1.05 7.43 × 104
7000 1.22 8.67 × 104
8000 1.39 9.91 × 104
9000 1.57 1.11 × 105
1.00 × 104 1.74 1.24 × 105
2.00 × 104 3.48 2.48 × 105
2.40 × 104 4.18 2.97 × 105
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.0176 557
30.0 0.0265 836
40.0 0.0353 1110
50.0 0.0441 1390
60.0 0.0529 1670
70.0 0.0617 1950
80.0 0.0706 2230
90.0 0.0794 2510
100 0.0882 2790
200 0.176 5570
300 0.265 8360
400 0.353 1.11 × 104
500 0.441 1.39 × 104
600 0.529 1.67 × 104
700 0.617 1.95 × 104
800 0.706 2.23 × 104
900 0.794 2.51 × 104
1000 0.882 2.79 × 104
2000 1.76 5.57 × 104
3000 2.65 8.36 × 104
4000 3.53 1.11 × 105
5000 4.41 1.39 × 105
6000 5.29 1.67 × 105
7000 6.17 1.95 × 105
7940 7.00 2.21 × 105
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.0558 991
30.0 0.0836 1490
40.0 0.112 1980
50.0 0.139 2480
60.0 0.167 2970
70.0 0.195 3470
80.0 0.223 3960
90.0 0.251 4460
100 0.279 4950
200 0.558 9910
300 0.836 1.49 × 104
400 1.12 1.98 × 104
500 1.39 2.48 × 104
600 1.67 2.97 × 104
700 1.95 3.47 × 104
800 2.23 3.96 × 104
900 2.51 4.46 × 104
1000 2.79 4.95 × 104
2000 5.58 9.91 × 104
2510 7.00 1.24 × 105
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.136 1550
30.0 0.204 2320
40.0 0.272 3100
50.0 0.340 3870
60.0 0.408 4640
70.0 0.476 5420
80.0 0.544 6190
90.0 0.613 6960
100 0.681 7740
200 1.36 1.55 × 104
300 2.04 2.32 × 104
400 2.72 3.10 × 104
500 3.40 3.87 × 104
600 4.08 4.64 × 104
700 4.76 5.42 × 104
800 5.44 6.19 × 104
900 6.13 6.96 × 104
1000 6.81 7.74 × 104
1030 7.00 7.96 × 104
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.282 2230
30.0 0.423 3340
40.0 0.564 4460
50.0 0.706 5570
60.0 0.847 6690
70.0 0.988 7800
80.0 1.13 8920
90.0 1.27 1.00 × 104
100 1.41 1.11 × 104
200 2.82 2.23 × 104
300 4.23 3.34 × 104
400 5.64 4.46 × 104
496 7.00 5.53 × 104
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 0.892 3960
30.0 1.34 5940
40.0 1.78 7920
50.0 2.23 9910
60.0 2.68 1.19 × 104
70.0 3.12 1.39 × 104
80.0 3.57 1.58 × 104
90.0 4.01 1.78 × 104
100 4.46 1.98 × 104
157 7.00 3.11 × 104
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 2.18 6190
30.0 3.27 9290
40.0 4.36 1.24 × 104
50.0 5.44 1.55 × 104
60.0 6.53 1.86 × 104
64.3 7.00 1.99 × 104
Steel I Beam: S7 × 20 (S Section 7 inch tall × 20 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
20.0 4.52 8920
30.0 6.77 1.34 × 104
31.0 7.00 1.38 × 104
Additional Information
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FREE Publications
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.

Mechanical Engineers Outlook

Guide for those interested in becoming a mechanical engineer. Includes qualifications, pay, and job duties.

Metal 3D Printing Design Guide

Direct Metal Laser Sintering (DMLS) 3D printing for parts with reduced cost and little waste.

more publications