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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Two Equal Spans » S Section Steel I Beam » S4 × 7.7
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 = 6.08 in4) for the S4 × 7.7 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
   
Steel I Beam: S4 × 7.7 (S4 inch tall × 7.7 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
7.70 3.03 × 10-5 34.2
8.00 3.15 × 10-5 35.5
9.00 3.54 × 10-5 40.0
10.0 3.94 × 10-5 44.4
20.0 7.87 × 10-5 88.8
30.0 1.18 × 10-4 133
40.0 1.57 × 10-4 178
50.0 1.97 × 10-4 222
60.0 2.36 × 10-4 266
70.0 2.76 × 10-4 311
80.0 3.15 × 10-4 355
90.0 3.54 × 10-4 400
100 3.94 × 10-4 444
200 7.87 × 10-4 888
300 0.00118 1330
400 0.00157 1780
500 0.00197 2220
600 0.00236 2660
700 0.00276 3110
800 0.00315 3550
900 0.00354 4000
1000 0.00394 4440
2000 0.00787 8880
3000 0.0118 1.33 × 104
4000 0.0157 1.78 × 104
5000 0.0197 2.22 × 104
6000 0.0236 2.66 × 104
7000 0.0276 3.11 × 104
8000 0.0315 3.55 × 104
9000 0.0354 4.00 × 104
1.00 × 104 0.0394 4.44 × 104
2.00 × 104 0.0787 8.88 × 104
3.00 × 104 0.118 1.33 × 105
4.00 × 104 0.157 1.78 × 105
5.00 × 104 0.197 2.22 × 105
6.00 × 104 0.236 2.66 × 105
6.69 × 104 0.263 2.97 × 105
Steel I Beam: S4 × 7.7 (S4 inch tall × 7.7 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
7.70 2.34 × 10-4 95.0
8.00 2.43 × 10-4 98.7
9.00 2.73 × 10-4 111
10.0 3.04 × 10-4 123
20.0 6.08 × 10-4 247
30.0 9.11 × 10-4 370
40.0 0.00122 493
50.0 0.00152 617
60.0 0.00182 740
70.0 0.00213 863
80.0 0.00243 987
90.0 0.00273 1110
100 0.00304 1230
200 0.00608 2470
300 0.00911 3700
400 0.0122 4930
500 0.0152 6170
600 0.0182 7400
700 0.0213 8630
800 0.0243 9870
900 0.0273 1.11 × 104
1000 0.0304 1.23 × 104
2000 0.0608 2.47 × 104
3000 0.0911 3.70 × 104
4000 0.122 4.93 × 104
5000 0.152 6.17 × 104
6000 0.182 7.40 × 104
7000 0.213 8.63 × 104
8000 0.243 9.87 × 104
9000 0.273 1.11 × 105
1.00 × 104 0.304 1.23 × 105
2.00 × 104 0.608 2.47 × 105
2.41 × 104 0.731 2.97 × 105
Steel I Beam: S4 × 7.7 (S4 inch tall × 7.7 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
7.70 0.00374 380
8.00 0.00389 395
9.00 0.00437 444
10.0 0.00486 493
20.0 0.00972 987
30.0 0.0146 1480
40.0 0.0194 1970
50.0 0.0243 2470
60.0 0.0292 2960
70.0 0.0340 3450
80.0 0.0389 3950
90.0 0.0437 4440
100 0.0486 4930
200 0.0972 9870
300 0.146 1.48 × 104
400 0.194 1.97 × 104
500 0.243 2.47 × 104
600 0.292 2.96 × 104
700 0.340 3.45 × 104
800 0.389 3.95 × 104
900 0.437 4.44 × 104
1000 0.486 4.93 × 104
2000 0.972 9.87 × 104
3000 1.46 1.48 × 105
4000 1.94 1.97 × 105
5000 2.43 2.47 × 105
6000 2.92 2.96 × 105
6020 2.93 2.97 × 105
Steel I Beam: S4 × 7.7 (S4 inch tall × 7.7 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
7.70 0.0189 855
8.00 0.0197 888
9.00 0.0221 999
10.0 0.0246 1110
20.0 0.0492 2220
30.0 0.0738 3330
40.0 0.0984 4440
50.0 0.123 5550
60.0 0.148 6660
70.0 0.172 7770
80.0 0.197 8880
90.0 0.221 9990
100 0.246 1.11 × 104
200 0.492 2.22 × 104
300 0.738 3.33 × 104
400 0.984 4.44 × 104
500 1.23 5.55 × 104
600 1.48 6.66 × 104
700 1.72 7.77 × 104
800 1.97 8.88 × 104
900 2.21 9.99 × 104
1000 2.46 1.11 × 105
1630 4.00 1.80 × 105
Steel I Beam: S4 × 7.7 (S4 inch tall × 7.7 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
7.70 0.0599 1520
8.00 0.0622 1580
9.00 0.0700 1780
10.0 0.0778 1970
20.0 0.156 3950
30.0 0.233 5920
40.0 0.311 7890
50.0 0.389 9870
60.0 0.467 1.18 × 104
70.0 0.544 1.38 × 104
80.0 0.622 1.58 × 104
90.0 0.700 1.78 × 104
100 0.778 1.97 × 104
200 1.56 3.95 × 104
300 2.33 5.92 × 104
400 3.11 7.89 × 104
500 3.89 9.87 × 104
514 4.00 1.02 × 105
Steel I Beam: S4 × 7.7 (S4 inch tall × 7.7 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
7.70 0.146 2370
8.00 0.152 2470
9.00 0.171 2780
10.0 0.190 3080
20.0 0.380 6170
30.0 0.570 9250
40.0 0.759 1.23 × 104
50.0 0.949 1.54 × 104
60.0 1.14 1.85 × 104
70.0 1.33 2.16 × 104
80.0 1.52 2.47 × 104
90.0 1.71 2.78 × 104
100 1.90 3.08 × 104
200 3.80 6.17 × 104
211 4.00 6.50 × 104
Steel I Beam: S4 × 7.7 (S4 inch tall × 7.7 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
7.70 0.303 3420
8.00 0.315 3550
9.00 0.354 4000
10.0 0.394 4440
20.0 0.787 8880
30.0 1.18 1.33 × 104
40.0 1.57 1.78 × 104
50.0 1.97 2.22 × 104
60.0 2.36 2.66 × 104
70.0 2.76 3.11 × 104
80.0 3.15 3.55 × 104
90.0 3.54 4.00 × 104
100 3.94 4.44 × 104
102 4.00 4.51 × 104
Steel I Beam: S4 × 7.7 (S4 inch tall × 7.7 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
7.70 0.958 6080
8.00 0.995 6320
9.00 1.12 7110
10.0 1.24 7890
20.0 2.49 1.58 × 104
30.0 3.73 2.37 × 104
32.2 4.00 2.54 × 104
Steel I Beam: S4 × 7.7 (S4 inch tall × 7.7 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
7.70 2.34 9500
8.00 2.43 9870
9.00 2.73 1.11 × 104
10.0 3.04 1.23 × 104
13.2 4.00 1.62 × 104
Additional Information
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Metal 3D Printing Design Guide

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

STEM Career Outlook

Wages, employment opportunities, and growth projections for STEM jobs.

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