S Section Steel I Beam: S12 × 31.8

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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Three Equal Spans » S Section Steel I Beam » S12 × 31.8
S Section Steel I Beam | Single Span | Two Equal Spans | Three Equal Spans | Four Equal Spans

For a simply supported beam in three equal spans, we compute the displacement at the middle of the first and the third spans, and the maximum normal stress occuring at the second and third supports of the beam.
The tabulated data listed in this page are calculated based on the area moment of inertia (Ixx = 218 in4) for the S12 × 31.8 S Section Steel I Beam and the typical Young's modulus (E = 3.046 × 107 psi) of steels. Note that the typical yielding stress 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.

 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 3.00 ft (lbf/ft) (in) (psi) 31.8 4.56 × 10-6 9.45 40.0 5.73 × 10-6 11.9 50.0 7.17 × 10-6 14.9 60.0 8.60 × 10-6 17.8 70.0 1.00 × 10-5 20.8 80.0 1.15 × 10-5 23.8 90.0 1.29 × 10-5 26.8 100 1.43 × 10-5 29.7 200 2.87 × 10-5 59.4 300 4.30 × 10-5 89.2 400 5.73 × 10-5 119 500 7.17 × 10-5 149 600 8.60 × 10-5 178 700 1.00 × 10-4 208 800 1.15 × 10-4 238 900 1.29 × 10-4 268 1000 1.43 × 10-4 297 2000 2.87 × 10-4 594 3000 4.30 × 10-4 892 4000 5.73 × 10-4 1190 5000 7.17 × 10-4 1490 6000 8.60 × 10-4 1780 7000 0.00100 2080 8000 0.00115 2380 9000 0.00129 2680 1.00 × 104 0.00143 2970 2.00 × 104 0.00287 5940 3.00 × 104 0.00430 8920 4.00 × 104 0.00573 1.19 × 104 5.00 × 104 0.00717 1.49 × 104 6.00 × 104 0.00860 1.78 × 104 7.00 × 104 0.0100 2.08 × 104 8.00 × 104 0.0115 2.38 × 104 9.00 × 104 0.0129 2.68 × 104 1.00 × 105 0.0143 2.97 × 104 2.00 × 105 0.0287 5.94 × 104 3.00 × 105 0.0430 8.92 × 104 4.00 × 105 0.0573 1.19 × 105 5.00 × 105 0.0717 1.49 × 105 6.00 × 105 0.0860 1.78 × 105 7.00 × 105 0.100 2.08 × 105 8.00 × 105 0.115 2.38 × 105 9.00 × 105 0.129 2.68 × 105 9.99 × 105 0.143 2.97 × 105
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 5.00 ft (lbf/ft) (in) (psi) 31.8 3.52 × 10-5 26.3 40.0 4.42 × 10-5 33.0 50.0 5.53 × 10-5 41.3 60.0 6.64 × 10-5 49.5 70.0 7.74 × 10-5 57.8 80.0 8.85 × 10-5 66.1 90.0 9.95 × 10-5 74.3 100 1.11 × 10-4 82.6 200 2.21 × 10-4 165 300 3.32 × 10-4 248 400 4.42 × 10-4 330 500 5.53 × 10-4 413 600 6.64 × 10-4 495 700 7.74 × 10-4 578 800 8.85 × 10-4 661 900 9.95 × 10-4 743 1000 0.00111 826 2000 0.00221 1650 3000 0.00332 2480 4000 0.00442 3300 5000 0.00553 4130 6000 0.00664 4950 7000 0.00774 5780 8000 0.00885 6610 9000 0.00995 7430 1.00 × 104 0.0111 8260 2.00 × 104 0.0221 1.65 × 104 3.00 × 104 0.0332 2.48 × 104 4.00 × 104 0.0442 3.30 × 104 5.00 × 104 0.0553 4.13 × 104 6.00 × 104 0.0664 4.95 × 104 7.00 × 104 0.0774 5.78 × 104 8.00 × 104 0.0885 6.61 × 104 9.00 × 104 0.0995 7.43 × 104 1.00 × 105 0.111 8.26 × 104 2.00 × 105 0.221 1.65 × 105 3.00 × 105 0.332 2.48 × 105 3.60 × 105 0.398 2.97 × 105
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 10.0 ft (lbf/ft) (in) (psi) 31.8 5.63 × 10-4 105 40.0 7.08 × 10-4 132 50.0 8.85 × 10-4 165 60.0 0.00106 198 70.0 0.00124 231 80.0 0.00142 264 90.0 0.00159 297 100 0.00177 330 200 0.00354 661 300 0.00531 991 400 0.00708 1320 500 0.00885 1650 600 0.0106 1980 700 0.0124 2310 800 0.0142 2640 900 0.0159 2970 1000 0.0177 3300 2000 0.0354 6610 3000 0.0531 9910 4000 0.0708 1.32 × 104 5000 0.0885 1.65 × 104 6000 0.106 1.98 × 104 7000 0.124 2.31 × 104 8000 0.142 2.64 × 104 9000 0.159 2.97 × 104 1.00 × 104 0.177 3.30 × 104 2.00 × 104 0.354 6.61 × 104 3.00 × 104 0.531 9.91 × 104 4.00 × 104 0.708 1.32 × 105 5.00 × 104 0.885 1.65 × 105 6.00 × 104 1.06 1.98 × 105 7.00 × 104 1.24 2.31 × 105 8.00 × 104 1.42 2.64 × 105 8.99 × 104 1.59 2.97 × 105
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 15.0 ft (lbf/ft) (in) (psi) 31.8 0.00285 236 40.0 0.00358 297 50.0 0.00448 372 60.0 0.00538 446 70.0 0.00627 520 80.0 0.00717 594 90.0 0.00806 669 100 0.00896 743 200 0.0179 1490 300 0.0269 2230 400 0.0358 2970 500 0.0448 3720 600 0.0538 4460 700 0.0627 5200 800 0.0717 5940 900 0.0806 6690 1000 0.0896 7430 2000 0.179 1.49 × 104 3000 0.269 2.23 × 104 4000 0.358 2.97 × 104 5000 0.448 3.72 × 104 6000 0.538 4.46 × 104 7000 0.627 5.20 × 104 8000 0.717 5.94 × 104 9000 0.806 6.69 × 104 1.00 × 104 0.896 7.43 × 104 2.00 × 104 1.79 1.49 × 105 3.00 × 104 2.69 2.23 × 105 4.00 × 104 3.58 2.97 × 105
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 20.0 ft (lbf/ft) (in) (psi) 31.8 0.00900 420 40.0 0.0113 528 50.0 0.0142 661 60.0 0.0170 793 70.0 0.0198 925 80.0 0.0227 1060 90.0 0.0255 1190 100 0.0283 1320 200 0.0566 2640 300 0.0849 3960 400 0.113 5280 500 0.142 6610 600 0.170 7930 700 0.198 9250 800 0.227 1.06 × 104 900 0.255 1.19 × 104 1000 0.283 1.32 × 104 2000 0.566 2.64 × 104 3000 0.849 3.96 × 104 4000 1.13 5.28 × 104 5000 1.42 6.61 × 104 6000 1.70 7.93 × 104 7000 1.98 9.25 × 104 8000 2.27 1.06 × 105 9000 2.55 1.19 × 105 1.00 × 104 2.83 1.32 × 105 2.00 × 104 5.66 2.64 × 105 2.25 × 104 6.37 2.97 × 105
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 25.0 ft (lbf/ft) (in) (psi) 31.8 0.0220 656 40.0 0.0277 826 50.0 0.0346 1030 60.0 0.0415 1240 70.0 0.0484 1440 80.0 0.0553 1650 90.0 0.0622 1860 100 0.0691 2060 200 0.138 4130 300 0.207 6190 400 0.277 8260 500 0.346 1.03 × 104 600 0.415 1.24 × 104 700 0.484 1.44 × 104 800 0.553 1.65 × 104 900 0.622 1.86 × 104 1000 0.691 2.06 × 104 2000 1.38 4.13 × 104 3000 2.07 6.19 × 104 4000 2.77 8.26 × 104 5000 3.46 1.03 × 105 6000 4.15 1.24 × 105 7000 4.84 1.44 × 105 8000 5.53 1.65 × 105 9000 6.22 1.86 × 105 1.00 × 104 6.91 2.06 × 105 1.44 × 104 9.95 2.97 × 105
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 30.0 ft (lbf/ft) (in) (psi) 31.8 0.0456 945 40.0 0.0573 1190 50.0 0.0717 1490 60.0 0.0860 1780 70.0 0.100 2080 80.0 0.115 2380 90.0 0.129 2680 100 0.143 2970 200 0.287 5940 300 0.430 8920 400 0.573 1.19 × 104 500 0.717 1.49 × 104 600 0.860 1.78 × 104 700 1.00 2.08 × 104 800 1.15 2.38 × 104 900 1.29 2.68 × 104 1000 1.43 2.97 × 104 2000 2.87 5.94 × 104 3000 4.30 8.92 × 104 4000 5.73 1.19 × 105 5000 7.17 1.49 × 105 6000 8.60 1.78 × 105 7000 10.0 2.08 × 105 8000 11.5 2.38 × 105 8370 12.0 2.49 × 105
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 40.0 ft (lbf/ft) (in) (psi) 31.8 0.144 1680 40.0 0.181 2110 50.0 0.227 2640 60.0 0.272 3170 70.0 0.317 3700 80.0 0.362 4230 90.0 0.408 4760 100 0.453 5280 200 0.906 1.06 × 104 300 1.36 1.59 × 104 400 1.81 2.11 × 104 500 2.27 2.64 × 104 600 2.72 3.17 × 104 700 3.17 3.70 × 104 800 3.62 4.23 × 104 900 4.08 4.76 × 104 1000 4.53 5.28 × 104 2000 9.06 1.06 × 105 2650 12.0 1.40 × 105
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 50.0 ft (lbf/ft) (in) (psi) 31.8 0.352 2630 40.0 0.442 3300 50.0 0.553 4130 60.0 0.664 4950 70.0 0.774 5780 80.0 0.885 6610 90.0 0.995 7430 100 1.11 8260 200 2.21 1.65 × 104 300 3.32 2.48 × 104 400 4.42 3.30 × 104 500 5.53 4.13 × 104 600 6.64 4.95 × 104 700 7.74 5.78 × 104 800 8.85 6.61 × 104 900 9.95 7.43 × 104 1000 11.1 8.26 × 104 1080 12.0 8.96 × 104
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 60.0 ft (lbf/ft) (in) (psi) 31.8 0.729 3780 40.0 0.917 4760 50.0 1.15 5940 60.0 1.38 7130 70.0 1.61 8320 80.0 1.83 9510 90.0 2.06 1.07 × 104 100 2.29 1.19 × 104 200 4.59 2.38 × 104 300 6.88 3.57 × 104 400 9.17 4.76 × 104 500 11.5 5.94 × 104 523 12.0 6.22 × 104
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 70.0 ft (lbf/ft) (in) (psi) 31.8 1.35 5150 40.0 1.70 6470 50.0 2.12 8090 60.0 2.55 9710 70.0 2.97 1.13 × 104 80.0 3.40 1.29 × 104 90.0 3.82 1.46 × 104 100 4.25 1.62 × 104 200 8.50 3.24 × 104 282 12.0 4.57 × 104
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 80.0 ft (lbf/ft) (in) (psi) 31.8 2.31 6720 40.0 2.90 8460 50.0 3.62 1.06 × 104 60.0 4.35 1.27 × 104 70.0 5.07 1.48 × 104 80.0 5.80 1.69 × 104 90.0 6.52 1.90 × 104 100 7.25 2.11 × 104 166 12.0 3.50 × 104
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 90.0 ft (lbf/ft) (in) (psi) 31.8 3.69 8510 40.0 4.64 1.07 × 104 50.0 5.81 1.34 × 104 60.0 6.97 1.61 × 104 70.0 8.13 1.87 × 104 80.0 9.29 2.14 × 104 90.0 10.4 2.41 × 104 100 11.6 2.68 × 104 103 12.0 2.76 × 104
 Steel I Beam: S12 × 31.8 (S12 inch tall × 31.8 lbf/ft) L = 100 ft (lbf/ft) (in) (psi) 31.8 5.63 1.05 × 104 40.0 7.08 1.32 × 104 50.0 8.85 1.65 × 104 60.0 10.6 1.98 × 104 67.8 12.0 2.24 × 104