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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Single Span » S Section Steel I Beam » S18 × 70
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 = 926 in4) for the S18 × 70 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
L = 90 ft
L = 100 ft
L = 125 ft
   
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 4.52 × 10-6 9.18
80.0 5.17 × 10-6 10.5
90.0 5.82 × 10-6 11.8
100 6.46 × 10-6 13.1
200 1.29 × 10-5 26.2
300 1.94 × 10-5 39.4
400 2.58 × 10-5 52.5
500 3.23 × 10-5 65.6
600 3.88 × 10-5 78.7
700 4.52 × 10-5 91.8
800 5.17 × 10-5 105
900 5.82 × 10-5 118
1000 6.46 × 10-5 131
2000 1.29 × 10-4 262
3000 1.94 × 10-4 394
4000 2.58 × 10-4 525
5000 3.23 × 10-4 656
6000 3.88 × 10-4 787
7000 4.52 × 10-4 918
8000 5.17 × 10-4 1050
9000 5.82 × 10-4 1180
1.00 × 104 6.46 × 10-4 1310
2.00 × 104 0.00129 2620
3.00 × 104 0.00194 3940
4.00 × 104 0.00258 5250
5.00 × 104 0.00323 6560
6.00 × 104 0.00388 7870
7.00 × 104 0.00452 9180
8.00 × 104 0.00517 1.05 × 104
9.00 × 104 0.00582 1.18 × 104
1.00 × 105 0.00646 1.31 × 104
2.00 × 105 0.0129 2.62 × 104
3.00 × 105 0.0194 3.94 × 104
4.00 × 105 0.0258 5.25 × 104
5.00 × 105 0.0323 6.56 × 104
6.00 × 105 0.0388 7.87 × 104
7.00 × 105 0.0452 9.18 × 104
8.00 × 105 0.0517 1.05 × 105
9.00 × 105 0.0582 1.18 × 105
1.00 × 106 0.0646 1.31 × 105
2.00 × 106 0.129 2.62 × 105
2.26 × 106 0.146 2.97 × 105
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 3.49 × 10-5 25.5
80.0 3.99 × 10-5 29.2
90.0 4.49 × 10-5 32.8
100 4.99 × 10-5 36.4
200 9.97 × 10-5 72.9
300 1.50 × 10-4 109
400 1.99 × 10-4 146
500 2.49 × 10-4 182
600 2.99 × 10-4 219
700 3.49 × 10-4 255
800 3.99 × 10-4 292
900 4.49 × 10-4 328
1000 4.99 × 10-4 364
2000 9.97 × 10-4 729
3000 0.00150 1090
4000 0.00199 1460
5000 0.00249 1820
6000 0.00299 2190
7000 0.00349 2550
8000 0.00399 2920
9000 0.00449 3280
1.00 × 104 0.00499 3640
2.00 × 104 0.00997 7290
3.00 × 104 0.0150 1.09 × 104
4.00 × 104 0.0199 1.46 × 104
5.00 × 104 0.0249 1.82 × 104
6.00 × 104 0.0299 2.19 × 104
7.00 × 104 0.0349 2.55 × 104
8.00 × 104 0.0399 2.92 × 104
9.00 × 104 0.0449 3.28 × 104
1.00 × 105 0.0499 3.64 × 104
2.00 × 105 0.0997 7.29 × 104
3.00 × 105 0.150 1.09 × 105
4.00 × 105 0.199 1.46 × 105
5.00 × 105 0.249 1.82 × 105
6.00 × 105 0.299 2.19 × 105
7.00 × 105 0.349 2.55 × 105
8.00 × 105 0.399 2.92 × 105
8.15 × 105 0.406 2.97 × 105
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 5.58 × 10-4 102
80.0 6.38 × 10-4 117
90.0 7.18 × 10-4 131
100 7.98 × 10-4 146
200 0.00160 292
300 0.00239 437
400 0.00319 583
500 0.00399 729
600 0.00479 875
700 0.00558 1020
800 0.00638 1170
900 0.00718 1310
1000 0.00798 1460
2000 0.0160 2920
3000 0.0239 4370
4000 0.0319 5830
5000 0.0399 7290
6000 0.0479 8750
7000 0.0558 1.02 × 104
8000 0.0638 1.17 × 104
9000 0.0718 1.31 × 104
1.00 × 104 0.0798 1.46 × 104
2.00 × 104 0.160 2.92 × 104
3.00 × 104 0.239 4.37 × 104
4.00 × 104 0.319 5.83 × 104
5.00 × 104 0.399 7.29 × 104
6.00 × 104 0.479 8.75 × 104
7.00 × 104 0.558 1.02 × 105
8.00 × 104 0.638 1.17 × 105
9.00 × 104 0.718 1.31 × 105
1.00 × 105 0.798 1.46 × 105
2.00 × 105 1.60 2.92 × 105
2.04 × 105 1.63 2.97 × 105
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 0.00283 230
80.0 0.00323 262
90.0 0.00363 295
100 0.00404 328
200 0.00808 656
300 0.0121 984
400 0.0162 1310
500 0.0202 1640
600 0.0242 1970
700 0.0283 2300
800 0.0323 2620
900 0.0363 2950
1000 0.0404 3280
2000 0.0808 6560
3000 0.121 9840
4000 0.162 1.31 × 104
5000 0.202 1.64 × 104
6000 0.242 1.97 × 104
7000 0.283 2.30 × 104
8000 0.323 2.62 × 104
9000 0.363 2.95 × 104
1.00 × 104 0.404 3.28 × 104
2.00 × 104 0.808 6.56 × 104
3.00 × 104 1.21 9.84 × 104
4.00 × 104 1.62 1.31 × 105
5.00 × 104 2.02 1.64 × 105
6.00 × 104 2.42 1.97 × 105
7.00 × 104 2.83 2.30 × 105
8.00 × 104 3.23 2.62 × 105
9.00 × 104 3.63 2.95 × 105
9.06 × 104 3.66 2.97 × 105
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 0.00893 408
80.0 0.0102 467
90.0 0.0115 525
100 0.0128 583
200 0.0255 1170
300 0.0383 1750
400 0.0511 2330
500 0.0638 2920
600 0.0766 3500
700 0.0893 4080
800 0.102 4670
900 0.115 5250
1000 0.128 5830
2000 0.255 1.17 × 104
3000 0.383 1.75 × 104
4000 0.511 2.33 × 104
5000 0.638 2.92 × 104
6000 0.766 3.50 × 104
7000 0.893 4.08 × 104
8000 1.02 4.67 × 104
9000 1.15 5.25 × 104
1.00 × 104 1.28 5.83 × 104
2.00 × 104 2.55 1.17 × 105
3.00 × 104 3.83 1.75 × 105
4.00 × 104 5.11 2.33 × 105
5.00 × 104 6.38 2.92 × 105
5.09 × 104 6.50 2.97 × 105
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 0.0218 638
80.0 0.0249 729
90.0 0.0280 820
100 0.0312 911
200 0.0623 1820
300 0.0935 2730
400 0.125 3640
500 0.156 4560
600 0.187 5470
700 0.218 6380
800 0.249 7290
900 0.280 8200
1000 0.312 9110
2000 0.623 1.82 × 104
3000 0.935 2.73 × 104
4000 1.25 3.64 × 104
5000 1.56 4.56 × 104
6000 1.87 5.47 × 104
7000 2.18 6.38 × 104
8000 2.49 7.29 × 104
9000 2.80 8.20 × 104
1.00 × 104 3.12 9.11 × 104
2.00 × 104 6.23 1.82 × 105
3.00 × 104 9.35 2.73 × 105
3.26 × 104 10.2 2.97 × 105
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 0.0452 918
80.0 0.0517 1050
90.0 0.0582 1180
100 0.0646 1310
200 0.129 2620
300 0.194 3940
400 0.258 5250
500 0.323 6560
600 0.388 7870
700 0.452 9180
800 0.517 1.05 × 104
900 0.582 1.18 × 104
1000 0.646 1.31 × 104
2000 1.29 2.62 × 104
3000 1.94 3.94 × 104
4000 2.58 5.25 × 104
5000 3.23 6.56 × 104
6000 3.88 7.87 × 104
7000 4.52 9.18 × 104
8000 5.17 1.05 × 105
9000 5.82 1.18 × 105
1.00 × 104 6.46 1.31 × 105
2.00 × 104 12.9 2.62 × 105
2.26 × 104 14.6 2.97 × 105
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 0.143 1630
80.0 0.163 1870
90.0 0.184 2100
100 0.204 2330
200 0.408 4670
300 0.613 7000
400 0.817 9330
500 1.02 1.17 × 104
600 1.23 1.40 × 104
700 1.43 1.63 × 104
800 1.63 1.87 × 104
900 1.84 2.10 × 104
1000 2.04 2.33 × 104
2000 4.08 4.67 × 104
3000 6.13 7.00 × 104
4000 8.17 9.33 × 104
5000 10.2 1.17 × 105
6000 12.3 1.40 × 105
7000 14.3 1.63 × 105
8000 16.3 1.87 × 105
8810 18.0 2.06 × 105
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 0.349 2550
80.0 0.399 2920
90.0 0.449 3280
100 0.499 3640
200 0.997 7290
300 1.50 1.09 × 104
400 1.99 1.46 × 104
500 2.49 1.82 × 104
600 2.99 2.19 × 104
700 3.49 2.55 × 104
800 3.99 2.92 × 104
900 4.49 3.28 × 104
1000 4.99 3.64 × 104
2000 9.97 7.29 × 104
3000 15.0 1.09 × 105
3610 18.0 1.32 × 105
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 0.724 3670
80.0 0.827 4200
90.0 0.931 4720
100 1.03 5250
200 2.07 1.05 × 104
300 3.10 1.57 × 104
400 4.14 2.10 × 104
500 5.17 2.62 × 104
600 6.20 3.15 × 104
700 7.24 3.67 × 104
800 8.27 4.20 × 104
900 9.31 4.72 × 104
1000 10.3 5.25 × 104
1740 18.0 9.14 × 104
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 70.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 1.34 5000
80.0 1.53 5710
90.0 1.72 6430
100 1.92 7140
200 3.83 1.43 × 104
300 5.75 2.14 × 104
400 7.66 2.86 × 104
500 9.58 3.57 × 104
600 11.5 4.29 × 104
700 13.4 5.00 × 104
800 15.3 5.71 × 104
900 17.2 6.43 × 104
940 18.0 6.71 × 104
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 80.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 2.29 6530
80.0 2.61 7460
90.0 2.94 8400
100 3.27 9330
200 6.54 1.87 × 104
300 9.80 2.80 × 104
400 13.1 3.73 × 104
500 16.3 4.67 × 104
551 18.0 5.14 × 104
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 90.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 3.66 8270
80.0 4.19 9450
90.0 4.71 1.06 × 104
100 5.23 1.18 × 104
200 10.5 2.36 × 104
300 15.7 3.54 × 104
344 18.0 4.06 × 104
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 100 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 5.58 1.02 × 104
80.0 6.38 1.17 × 104
90.0 7.18 1.31 × 104
100 7.98 1.46 × 104
200 16.0 2.92 × 104
226 18.0 3.29 × 104
Steel I Beam: S18 × 70 (S Section 18 inch tall × 70 lbf/ft)
L = 125 ft
P (lbf/ft) w_max (in) stress_max (psi)
70.0 13.6 1.59 × 104
80.0 15.6 1.82 × 104
90.0 17.5 2.05 × 104
92.4 18.0 2.11 × 104
Additional Information
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CNC Machining Design Guide

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

Essentials of Manufacturing

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

Selecting the Right 3D Printer

Discover how to choose the right 3D printer for your needs and the key performance attributes to consider.

3D Scanners

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

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