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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Two Equal Spans » Wide Flange Steel I Beam » W18 × 35
Wide Flange 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 = 510 in4) for the W18 × 35 Wide Flange 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
L = 90 ft
L = 100 ft
L = 125 ft
L = 150 ft
   
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 1.64 × 10-6 8.20
40.0 1.88 × 10-6 9.37
50.0 2.35 × 10-6 11.7
60.0 2.82 × 10-6 14.1
70.0 3.29 × 10-6 16.4
80.0 3.75 × 10-6 18.7
90.0 4.22 × 10-6 21.1
100 4.69 × 10-6 23.4
200 9.39 × 10-6 46.9
300 1.41 × 10-5 70.3
400 1.88 × 10-5 93.7
500 2.35 × 10-5 117
600 2.82 × 10-5 141
700 3.29 × 10-5 164
800 3.75 × 10-5 187
900 4.22 × 10-5 211
1000 4.69 × 10-5 234
2000 9.39 × 10-5 469
3000 1.41 × 10-4 703
4000 1.88 × 10-4 937
5000 2.35 × 10-4 1170
6000 2.82 × 10-4 1410
7000 3.29 × 10-4 1640
8000 3.75 × 10-4 1870
9000 4.22 × 10-4 2110
1.00 × 104 4.69 × 10-4 2340
2.00 × 104 9.39 × 10-4 4690
3.00 × 104 0.00141 7030
4.00 × 104 0.00188 9370
5.00 × 104 0.00235 1.17 × 104
6.00 × 104 0.00282 1.41 × 104
7.00 × 104 0.00329 1.64 × 104
8.00 × 104 0.00375 1.87 × 104
9.00 × 104 0.00422 2.11 × 104
1.00 × 105 0.00469 2.34 × 104
2.00 × 105 0.00939 4.69 × 104
3.00 × 105 0.0141 7.03 × 104
4.00 × 105 0.0188 9.37 × 104
5.00 × 105 0.0235 1.17 × 105
6.00 × 105 0.0282 1.41 × 105
7.00 × 105 0.0329 1.64 × 105
8.00 × 105 0.0375 1.87 × 105
9.00 × 105 0.0422 2.11 × 105
1.00 × 106 0.0469 2.34 × 105
1.27 × 106 0.0595 2.97 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 1.27 × 10-5 22.8
40.0 1.45 × 10-5 26.0
50.0 1.81 × 10-5 32.5
60.0 2.17 × 10-5 39.0
70.0 2.53 × 10-5 45.6
80.0 2.90 × 10-5 52.1
90.0 3.26 × 10-5 58.6
100 3.62 × 10-5 65.1
200 7.24 × 10-5 130
300 1.09 × 10-4 195
400 1.45 × 10-4 260
500 1.81 × 10-4 325
600 2.17 × 10-4 390
700 2.53 × 10-4 456
800 2.90 × 10-4 521
900 3.26 × 10-4 586
1000 3.62 × 10-4 651
2000 7.24 × 10-4 1300
3000 0.00109 1950
4000 0.00145 2600
5000 0.00181 3250
6000 0.00217 3900
7000 0.00253 4560
8000 0.00290 5210
9000 0.00326 5860
1.00 × 104 0.00362 6510
2.00 × 104 0.00724 1.30 × 104
3.00 × 104 0.0109 1.95 × 104
4.00 × 104 0.0145 2.60 × 104
5.00 × 104 0.0181 3.25 × 104
6.00 × 104 0.0217 3.90 × 104
7.00 × 104 0.0253 4.56 × 104
8.00 × 104 0.0290 5.21 × 104
9.00 × 104 0.0326 5.86 × 104
1.00 × 105 0.0362 6.51 × 104
2.00 × 105 0.0724 1.30 × 105
3.00 × 105 0.109 1.95 × 105
4.00 × 105 0.145 2.60 × 105
4.56 × 105 0.165 2.97 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 2.03 × 10-4 91.1
40.0 2.32 × 10-4 104
50.0 2.90 × 10-4 130
60.0 3.48 × 10-4 156
70.0 4.06 × 10-4 182
80.0 4.64 × 10-4 208
90.0 5.21 × 10-4 234
100 5.79 × 10-4 260
200 0.00116 521
300 0.00174 781
400 0.00232 1040
500 0.00290 1300
600 0.00348 1560
700 0.00406 1820
800 0.00464 2080
900 0.00521 2340
1000 0.00579 2600
2000 0.0116 5210
3000 0.0174 7810
4000 0.0232 1.04 × 104
5000 0.0290 1.30 × 104
6000 0.0348 1.56 × 104
7000 0.0406 1.82 × 104
8000 0.0464 2.08 × 104
9000 0.0521 2.34 × 104
1.00 × 104 0.0579 2.60 × 104
2.00 × 104 0.116 5.21 × 104
3.00 × 104 0.174 7.81 × 104
4.00 × 104 0.232 1.04 × 105
5.00 × 104 0.290 1.30 × 105
6.00 × 104 0.348 1.56 × 105
7.00 × 104 0.406 1.82 × 105
8.00 × 104 0.464 2.08 × 105
9.00 × 104 0.521 2.34 × 105
1.00 × 105 0.579 2.60 × 105
1.14 × 105 0.661 2.97 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 0.00103 205
40.0 0.00117 234
50.0 0.00147 293
60.0 0.00176 351
70.0 0.00205 410
80.0 0.00235 469
90.0 0.00264 527
100 0.00293 586
200 0.00587 1170
300 0.00880 1760
400 0.0117 2340
500 0.0147 2930
600 0.0176 3510
700 0.0205 4100
800 0.0235 4690
900 0.0264 5270
1000 0.0293 5860
2000 0.0587 1.17 × 104
3000 0.0880 1.76 × 104
4000 0.117 2.34 × 104
5000 0.147 2.93 × 104
6000 0.176 3.51 × 104
7000 0.205 4.10 × 104
8000 0.235 4.69 × 104
9000 0.264 5.27 × 104
1.00 × 104 0.293 5.86 × 104
2.00 × 104 0.587 1.17 × 105
3.00 × 104 0.880 1.76 × 105
4.00 × 104 1.17 2.34 × 105
5.00 × 104 1.47 2.93 × 105
5.07 × 104 1.49 2.97 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 0.00324 364
40.0 0.00371 416
50.0 0.00464 521
60.0 0.00556 625
70.0 0.00649 729
80.0 0.00742 833
90.0 0.00834 937
100 0.00927 1040
200 0.0185 2080
300 0.0278 3120
400 0.0371 4160
500 0.0464 5210
600 0.0556 6250
700 0.0649 7290
800 0.0742 8330
900 0.0834 9370
1000 0.0927 1.04 × 104
2000 0.185 2.08 × 104
3000 0.278 3.12 × 104
4000 0.371 4.16 × 104
5000 0.464 5.21 × 104
6000 0.556 6.25 × 104
7000 0.649 7.29 × 104
8000 0.742 8.33 × 104
9000 0.834 9.37 × 104
1.00 × 104 0.927 1.04 × 105
2.00 × 104 1.85 2.08 × 105
2.85 × 104 2.64 2.97 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 0.00792 569
40.0 0.00905 651
50.0 0.0113 813
60.0 0.0136 976
70.0 0.0158 1140
80.0 0.0181 1300
90.0 0.0204 1460
100 0.0226 1630
200 0.0453 3250
300 0.0679 4880
400 0.0905 6510
500 0.113 8130
600 0.136 9760
700 0.158 1.14 × 104
800 0.181 1.30 × 104
900 0.204 1.46 × 104
1000 0.226 1.63 × 104
2000 0.453 3.25 × 104
3000 0.679 4.88 × 104
4000 0.905 6.51 × 104
5000 1.13 8.13 × 104
6000 1.36 9.76 × 104
7000 1.58 1.14 × 105
8000 1.81 1.30 × 105
9000 2.04 1.46 × 105
1.00 × 104 2.26 1.63 × 105
1.83 × 104 4.13 2.97 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 0.0164 820
40.0 0.0188 937
50.0 0.0235 1170
60.0 0.0282 1410
70.0 0.0329 1640
80.0 0.0375 1870
90.0 0.0422 2110
100 0.0469 2340
200 0.0939 4690
300 0.141 7030
400 0.188 9370
500 0.235 1.17 × 104
600 0.282 1.41 × 104
700 0.329 1.64 × 104
800 0.375 1.87 × 104
900 0.422 2.11 × 104
1000 0.469 2.34 × 104
2000 0.939 4.69 × 104
3000 1.41 7.03 × 104
4000 1.88 9.37 × 104
5000 2.35 1.17 × 105
6000 2.82 1.41 × 105
7000 3.29 1.64 × 105
8000 3.75 1.87 × 105
9000 4.22 2.11 × 105
1.00 × 104 4.69 2.34 × 105
1.27 × 104 5.95 2.97 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 0.0519 1460
40.0 0.0593 1670
50.0 0.0742 2080
60.0 0.0890 2500
70.0 0.104 2920
80.0 0.119 3330
90.0 0.133 3750
100 0.148 4160
200 0.297 8330
300 0.445 1.25 × 104
400 0.593 1.67 × 104
500 0.742 2.08 × 104
600 0.890 2.50 × 104
700 1.04 2.92 × 104
800 1.19 3.33 × 104
900 1.33 3.75 × 104
1000 1.48 4.16 × 104
2000 2.97 8.33 × 104
3000 4.45 1.25 × 105
4000 5.93 1.67 × 105
5000 7.42 2.08 × 105
6000 8.90 2.50 × 105
7000 10.4 2.92 × 105
7130 10.6 2.97 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 0.127 2280
40.0 0.145 2600
50.0 0.181 3250
60.0 0.217 3900
70.0 0.253 4560
80.0 0.290 5210
90.0 0.326 5860
100 0.362 6510
200 0.724 1.30 × 104
300 1.09 1.95 × 104
400 1.45 2.60 × 104
500 1.81 3.25 × 104
600 2.17 3.90 × 104
700 2.53 4.56 × 104
800 2.90 5.21 × 104
900 3.26 5.86 × 104
1000 3.62 6.51 × 104
2000 7.24 1.30 × 105
3000 10.9 1.95 × 105
4000 14.5 2.60 × 105
4560 16.5 2.97 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 0.263 3280
40.0 0.300 3750
50.0 0.375 4690
60.0 0.451 5620
70.0 0.526 6560
80.0 0.601 7500
90.0 0.676 8430
100 0.751 9370
200 1.50 1.87 × 104
300 2.25 2.81 × 104
400 3.00 3.75 × 104
500 3.75 4.69 × 104
600 4.51 5.62 × 104
700 5.26 6.56 × 104
800 6.01 7.50 × 104
900 6.76 8.43 × 104
1000 7.51 9.37 × 104
2000 15.0 1.87 × 105
2360 17.7 2.21 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 70.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 0.487 4460
40.0 0.556 5100
50.0 0.696 6380
60.0 0.835 7650
70.0 0.974 8930
80.0 1.11 1.02 × 104
90.0 1.25 1.15 × 104
100 1.39 1.28 × 104
200 2.78 2.55 × 104
300 4.17 3.83 × 104
400 5.56 5.10 × 104
500 6.96 6.38 × 104
600 8.35 7.65 × 104
700 9.74 8.93 × 104
800 11.1 1.02 × 105
900 12.5 1.15 × 105
1000 13.9 1.28 × 105
1270 17.7 1.62 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 80.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 0.831 5830
40.0 0.949 6660
50.0 1.19 8330
60.0 1.42 10000
70.0 1.66 1.17 × 104
80.0 1.90 1.33 × 104
90.0 2.14 1.50 × 104
100 2.37 1.67 × 104
200 4.75 3.33 × 104
300 7.12 5.00 × 104
400 9.49 6.66 × 104
500 11.9 8.33 × 104
600 14.2 1.00 × 105
700 16.6 1.17 × 105
746 17.7 1.24 × 105
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 90.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 1.33 7380
40.0 1.52 8430
50.0 1.90 1.05 × 104
60.0 2.28 1.27 × 104
70.0 2.66 1.48 × 104
80.0 3.04 1.69 × 104
90.0 3.42 1.90 × 104
100 3.80 2.11 × 104
200 7.60 4.22 × 104
300 11.4 6.33 × 104
400 15.2 8.43 × 104
466 17.7 9.82 × 104
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 100 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 2.03 9110
40.0 2.32 1.04 × 104
50.0 2.90 1.30 × 104
60.0 3.48 1.56 × 104
70.0 4.06 1.82 × 104
80.0 4.64 2.08 × 104
90.0 5.21 2.34 × 104
100 5.79 2.60 × 104
200 11.6 5.21 × 104
300 17.4 7.81 × 104
305 17.7 7.95 × 104
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 125 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 4.95 1.42 × 104
40.0 5.66 1.63 × 104
50.0 7.07 2.03 × 104
60.0 8.49 2.44 × 104
70.0 9.90 2.85 × 104
80.0 11.3 3.25 × 104
90.0 12.7 3.66 × 104
100 14.1 4.07 × 104
125 17.7 5.09 × 104
Steel I Beam: W18 × 35 (Wide Flange 18 inch tall × 35 lbf/ft)
L = 150 ft
P (lbf/ft) w_max (in) stress_max (psi)
35.0 10.3 2.05 × 104
40.0 11.7 2.34 × 104
50.0 14.7 2.93 × 104
60.0 17.6 3.51 × 104
60.3 17.7 3.53 × 104
Additional Information
Related Pages
FREE Publications
Injection Molding Design Guide

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

3D Scanners

A white paper to assist in the evaluation of 3D scanning hardware solutions.

Negotiate Your Salary

Learn the best principles to negotiate the salary you deserve!

Metal 3D Printing Design Guide

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

more publications