Wide Flange Steel I Beam: W8 × 18

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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Three Equal Spans » Wide Flange Steel I Beam » W8 × 18
Wide Flange 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 = 61.9 in4) for the W8 × 18 Wide Flange 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: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 3.00 ft (lbf/ft) (in) (psi) 18.0 9.09 × 10-6 12.8 20.0 1.01 × 10-5 14.2 30.0 1.51 × 10-5 21.3 40.0 2.02 × 10-5 28.4 50.0 2.52 × 10-5 35.5 60.0 3.03 × 10-5 42.6 70.0 3.53 × 10-5 49.7 80.0 4.04 × 10-5 56.8 90.0 4.54 × 10-5 63.9 100 5.05 × 10-5 71.0 200 1.01 × 10-4 142 300 1.51 × 10-4 213 400 2.02 × 10-4 284 500 2.52 × 10-4 355 600 3.03 × 10-4 426 700 3.53 × 10-4 497 800 4.04 × 10-4 568 900 4.54 × 10-4 639 1000 5.05 × 10-4 710 2000 0.00101 1420 3000 0.00151 2130 4000 0.00202 2840 5000 0.00252 3550 6000 0.00303 4260 7000 0.00353 4970 8000 0.00404 5680 9000 0.00454 6390 1.00 × 104 0.00505 7100 2.00 × 104 0.0101 1.42 × 104 3.00 × 104 0.0151 2.13 × 104 4.00 × 104 0.0202 2.84 × 104 5.00 × 104 0.0252 3.55 × 104 6.00 × 104 0.0303 4.26 × 104 7.00 × 104 0.0353 4.97 × 104 8.00 × 104 0.0404 5.68 × 104 9.00 × 104 0.0454 6.39 × 104 1.00 × 105 0.0505 7.10 × 104 2.00 × 105 0.101 1.42 × 105 3.00 × 105 0.151 2.13 × 105 4.00 × 105 0.202 2.84 × 105 4.18 × 105 0.211 2.97 × 105
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 5.00 ft (lbf/ft) (in) (psi) 18.0 7.01 × 10-5 35.5 20.0 7.79 × 10-5 39.5 30.0 1.17 × 10-4 59.2 40.0 1.56 × 10-4 78.9 50.0 1.95 × 10-4 98.6 60.0 2.34 × 10-4 118 70.0 2.73 × 10-4 138 80.0 3.12 × 10-4 158 90.0 3.51 × 10-4 178 100 3.90 × 10-4 197 200 7.79 × 10-4 395 300 0.00117 592 400 0.00156 789 500 0.00195 986 600 0.00234 1180 700 0.00273 1380 800 0.00312 1580 900 0.00351 1780 1000 0.00390 1970 2000 0.00779 3950 3000 0.0117 5920 4000 0.0156 7890 5000 0.0195 9860 6000 0.0234 1.18 × 104 7000 0.0273 1.38 × 104 8000 0.0312 1.58 × 104 9000 0.0351 1.78 × 104 1.00 × 104 0.0390 1.97 × 104 2.00 × 104 0.0779 3.95 × 104 3.00 × 104 0.117 5.92 × 104 4.00 × 104 0.156 7.89 × 104 5.00 × 104 0.195 9.86 × 104 6.00 × 104 0.234 1.18 × 105 7.00 × 104 0.273 1.38 × 105 8.00 × 104 0.312 1.58 × 105 9.00 × 104 0.351 1.78 × 105 1.00 × 105 0.390 1.97 × 105 1.51 × 105 0.587 2.97 × 105
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 10.0 ft (lbf/ft) (in) (psi) 18.0 0.00112 142 20.0 0.00125 158 30.0 0.00187 237 40.0 0.00249 316 50.0 0.00312 395 60.0 0.00374 473 70.0 0.00436 552 80.0 0.00499 631 90.0 0.00561 710 100 0.00623 789 200 0.0125 1580 300 0.0187 2370 400 0.0249 3160 500 0.0312 3950 600 0.0374 4730 700 0.0436 5520 800 0.0499 6310 900 0.0561 7100 1000 0.0623 7890 2000 0.125 1.58 × 104 3000 0.187 2.37 × 104 4000 0.249 3.16 × 104 5000 0.312 3.95 × 104 6000 0.374 4.73 × 104 7000 0.436 5.52 × 104 8000 0.499 6.31 × 104 9000 0.561 7.10 × 104 1.00 × 104 0.623 7.89 × 104 2.00 × 104 1.25 1.58 × 105 3.00 × 104 1.87 2.37 × 105 3.76 × 104 2.35 2.97 × 105
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 15.0 ft (lbf/ft) (in) (psi) 18.0 0.00568 320 20.0 0.00631 355 30.0 0.00947 533 40.0 0.0126 710 50.0 0.0158 888 60.0 0.0189 1070 70.0 0.0221 1240 80.0 0.0252 1420 90.0 0.0284 1600 100 0.0316 1780 200 0.0631 3550 300 0.0947 5330 400 0.126 7100 500 0.158 8880 600 0.189 1.07 × 104 700 0.221 1.24 × 104 800 0.252 1.42 × 104 900 0.284 1.60 × 104 1000 0.316 1.78 × 104 2000 0.631 3.55 × 104 3000 0.947 5.33 × 104 4000 1.26 7.10 × 104 5000 1.58 8.88 × 104 6000 1.89 1.07 × 105 7000 2.21 1.24 × 105 8000 2.52 1.42 × 105 9000 2.84 1.60 × 105 1.00 × 104 3.16 1.78 × 105 1.67 × 104 5.28 2.97 × 105
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 20.0 ft (lbf/ft) (in) (psi) 18.0 0.0179 568 20.0 0.0199 631 30.0 0.0299 947 40.0 0.0399 1260 50.0 0.0499 1580 60.0 0.0598 1890 70.0 0.0698 2210 80.0 0.0798 2520 90.0 0.0897 2840 100 0.0997 3160 200 0.199 6310 300 0.299 9470 400 0.399 1.26 × 104 500 0.499 1.58 × 104 600 0.598 1.89 × 104 700 0.698 2.21 × 104 800 0.798 2.52 × 104 900 0.897 2.84 × 104 1000 0.997 3.16 × 104 2000 1.99 6.31 × 104 3000 2.99 9.47 × 104 4000 3.99 1.26 × 105 5000 4.99 1.58 × 105 6000 5.98 1.89 × 105 7000 6.98 2.21 × 105 8000 7.98 2.52 × 105 8160 8.14 2.58 × 105
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 25.0 ft (lbf/ft) (in) (psi) 18.0 0.0438 888 20.0 0.0487 986 30.0 0.0730 1480 40.0 0.0974 1970 50.0 0.122 2470 60.0 0.146 2960 70.0 0.170 3450 80.0 0.195 3950 90.0 0.219 4440 100 0.243 4930 200 0.487 9860 300 0.730 1.48 × 104 400 0.974 1.97 × 104 500 1.22 2.47 × 104 600 1.46 2.96 × 104 700 1.70 3.45 × 104 800 1.95 3.95 × 104 900 2.19 4.44 × 104 1000 2.43 4.93 × 104 2000 4.87 9.86 × 104 3000 7.30 1.48 × 105 3340 8.14 1.65 × 105
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 30.0 ft (lbf/ft) (in) (psi) 18.0 0.0909 1280 20.0 0.101 1420 30.0 0.151 2130 40.0 0.202 2840 50.0 0.252 3550 60.0 0.303 4260 70.0 0.353 4970 80.0 0.404 5680 90.0 0.454 6390 100 0.505 7100 200 1.01 1.42 × 104 300 1.51 2.13 × 104 400 2.02 2.84 × 104 500 2.52 3.55 × 104 600 3.03 4.26 × 104 700 3.53 4.97 × 104 800 4.04 5.68 × 104 900 4.54 6.39 × 104 1000 5.05 7.10 × 104 1610 8.14 1.15 × 105
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 40.0 ft (lbf/ft) (in) (psi) 18.0 0.287 2270 20.0 0.319 2520 30.0 0.479 3790 40.0 0.638 5050 50.0 0.798 6310 60.0 0.957 7570 70.0 1.12 8840 80.0 1.28 1.01 × 104 90.0 1.44 1.14 × 104 100 1.60 1.26 × 104 200 3.19 2.52 × 104 300 4.79 3.79 × 104 400 6.38 5.05 × 104 500 7.98 6.31 × 104 510 8.14 6.44 × 104
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 50.0 ft (lbf/ft) (in) (psi) 18.0 0.701 3550 20.0 0.779 3950 30.0 1.17 5920 40.0 1.56 7890 50.0 1.95 9860 60.0 2.34 1.18 × 104 70.0 2.73 1.38 × 104 80.0 3.12 1.58 × 104 90.0 3.51 1.78 × 104 100 3.90 1.97 × 104 200 7.79 3.95 × 104 209 8.14 4.12 × 104
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 60.0 ft (lbf/ft) (in) (psi) 18.0 1.45 5110 20.0 1.62 5680 30.0 2.42 8520 40.0 3.23 1.14 × 104 50.0 4.04 1.42 × 104 60.0 4.85 1.70 × 104 70.0 5.65 1.99 × 104 80.0 6.46 2.27 × 104 90.0 7.27 2.56 × 104 100 8.08 2.84 × 104 101 8.14 2.86 × 104
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 70.0 ft (lbf/ft) (in) (psi) 18.0 2.69 6960 20.0 2.99 7730 30.0 4.49 1.16 × 104 40.0 5.99 1.55 × 104 50.0 7.48 1.93 × 104 54.4 8.14 2.10 × 104
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 80.0 ft (lbf/ft) (in) (psi) 18.0 4.60 9090 20.0 5.11 1.01 × 104 30.0 7.66 1.51 × 104 31.9 8.14 1.61 × 104
 Steel I Beam: W8 × 18 (Wide Flange 8 inch tall × 18 lbf/ft) L = 90.0 ft (lbf/ft) (in) (psi) 18.0 7.36 1.15 × 104 19.9 8.14 1.27 × 104