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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Single Span » S Section Steel I Beam » S8 × 18.4
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 = 57.6 in4) for the S8 × 18.4 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
   
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 1.91 × 10-5 17.2
20.0 2.08 × 10-5 18.8
30.0 3.12 × 10-5 28.1
40.0 4.16 × 10-5 37.5
50.0 5.19 × 10-5 46.9
60.0 6.23 × 10-5 56.3
70.0 7.27 × 10-5 65.6
80.0 8.31 × 10-5 75.0
90.0 9.35 × 10-5 84.4
100 1.04 × 10-4 93.8
200 2.08 × 10-4 188
300 3.12 × 10-4 281
400 4.16 × 10-4 375
500 5.19 × 10-4 469
600 6.23 × 10-4 563
700 7.27 × 10-4 656
800 8.31 × 10-4 750
900 9.35 × 10-4 844
1000 0.00104 938
2000 0.00208 1880
3000 0.00312 2810
4000 0.00416 3750
5000 0.00519 4690
6000 0.00623 5630
7000 0.00727 6560
8000 0.00831 7500
9000 0.00935 8440
1.00 × 104 0.0104 9380
2.00 × 104 0.0208 1.88 × 104
3.00 × 104 0.0312 2.81 × 104
4.00 × 104 0.0416 3.75 × 104
5.00 × 104 0.0519 4.69 × 104
6.00 × 104 0.0623 5.63 × 104
7.00 × 104 0.0727 6.56 × 104
8.00 × 104 0.0831 7.50 × 104
9.00 × 104 0.0935 8.44 × 104
1.00 × 105 0.104 9.38 × 104
2.00 × 105 0.208 1.88 × 105
3.00 × 105 0.312 2.81 × 105
3.17 × 105 0.329 2.97 × 105
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 1.47 × 10-4 47.9
20.0 1.60 × 10-4 52.1
30.0 2.40 × 10-4 78.1
40.0 3.21 × 10-4 104
50.0 4.01 × 10-4 130
60.0 4.81 × 10-4 156
70.0 5.61 × 10-4 182
80.0 6.41 × 10-4 208
90.0 7.21 × 10-4 234
100 8.02 × 10-4 260
200 0.00160 521
300 0.00240 781
400 0.00321 1040
500 0.00401 1300
600 0.00481 1560
700 0.00561 1820
800 0.00641 2080
900 0.00721 2340
1000 0.00802 2600
2000 0.0160 5210
3000 0.0240 7810
4000 0.0321 1.04 × 104
5000 0.0401 1.30 × 104
6000 0.0481 1.56 × 104
7000 0.0561 1.82 × 104
8000 0.0641 2.08 × 104
9000 0.0721 2.34 × 104
1.00 × 104 0.0802 2.60 × 104
2.00 × 104 0.160 5.21 × 104
3.00 × 104 0.240 7.81 × 104
4.00 × 104 0.321 1.04 × 105
5.00 × 104 0.401 1.30 × 105
6.00 × 104 0.481 1.56 × 105
7.00 × 104 0.561 1.82 × 105
8.00 × 104 0.641 2.08 × 105
9.00 × 104 0.721 2.34 × 105
1.00 × 105 0.802 2.60 × 105
1.14 × 105 0.914 2.97 × 105
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 0.00236 192
20.0 0.00257 208
30.0 0.00385 313
40.0 0.00513 417
50.0 0.00641 521
60.0 0.00770 625
70.0 0.00898 729
80.0 0.0103 833
90.0 0.0115 938
100 0.0128 1040
200 0.0257 2080
300 0.0385 3130
400 0.0513 4170
500 0.0641 5210
600 0.0770 6250
700 0.0898 7290
800 0.103 8330
900 0.115 9380
1000 0.128 1.04 × 104
2000 0.257 2.08 × 104
3000 0.385 3.13 × 104
4000 0.513 4.17 × 104
5000 0.641 5.21 × 104
6000 0.770 6.25 × 104
7000 0.898 7.29 × 104
8000 1.03 8.33 × 104
9000 1.15 9.38 × 104
1.00 × 104 1.28 1.04 × 105
2.00 × 104 2.57 2.08 × 105
2.85 × 104 3.66 2.97 × 105
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 0.0119 431
20.0 0.0130 469
30.0 0.0195 703
40.0 0.0260 938
50.0 0.0325 1170
60.0 0.0390 1410
70.0 0.0454 1640
80.0 0.0519 1880
90.0 0.0584 2110
100 0.0649 2340
200 0.130 4690
300 0.195 7030
400 0.260 9380
500 0.325 1.17 × 104
600 0.390 1.41 × 104
700 0.454 1.64 × 104
800 0.519 1.88 × 104
900 0.584 2.11 × 104
1000 0.649 2.34 × 104
2000 1.30 4.69 × 104
3000 1.95 7.03 × 104
4000 2.60 9.38 × 104
5000 3.25 1.17 × 105
6000 3.90 1.41 × 105
7000 4.54 1.64 × 105
8000 5.19 1.88 × 105
9000 5.84 2.11 × 105
1.00 × 104 6.49 2.34 × 105
1.27 × 104 8.23 2.97 × 105
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 0.0378 767
20.0 0.0410 833
30.0 0.0616 1250
40.0 0.0821 1670
50.0 0.103 2080
60.0 0.123 2500
70.0 0.144 2920
80.0 0.164 3330
90.0 0.185 3750
100 0.205 4170
200 0.410 8330
300 0.616 1.25 × 104
400 0.821 1.67 × 104
500 1.03 2.08 × 104
600 1.23 2.50 × 104
700 1.44 2.92 × 104
800 1.64 3.33 × 104
900 1.85 3.75 × 104
1000 2.05 4.17 × 104
2000 4.10 8.33 × 104
3000 6.16 1.25 × 105
3900 8.00 1.62 × 105
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 0.0922 1200
20.0 0.100 1300
30.0 0.150 1950
40.0 0.200 2600
50.0 0.250 3260
60.0 0.301 3910
70.0 0.351 4560
80.0 0.401 5210
90.0 0.451 5860
100 0.501 6510
200 1.00 1.30 × 104
300 1.50 1.95 × 104
400 2.00 2.60 × 104
500 2.50 3.26 × 104
600 3.01 3.91 × 104
700 3.51 4.56 × 104
800 4.01 5.21 × 104
900 4.51 5.86 × 104
1000 5.01 6.51 × 104
1600 8.00 1.04 × 105
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 0.191 1720
20.0 0.208 1880
30.0 0.312 2810
40.0 0.416 3750
50.0 0.519 4690
60.0 0.623 5630
70.0 0.727 6560
80.0 0.831 7500
90.0 0.935 8440
100 1.04 9380
200 2.08 1.88 × 104
300 3.12 2.81 × 104
400 4.16 3.75 × 104
500 5.19 4.69 × 104
600 6.23 5.63 × 104
700 7.27 6.56 × 104
770 8.00 7.22 × 104
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 0.604 3070
20.0 0.657 3330
30.0 0.985 5000
40.0 1.31 6670
50.0 1.64 8330
60.0 1.97 1.00 × 104
70.0 2.30 1.17 × 104
80.0 2.63 1.33 × 104
90.0 2.95 1.50 × 104
100 3.28 1.67 × 104
200 6.57 3.33 × 104
244 8.00 4.06 × 104
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 1.47 4790
20.0 1.60 5210
30.0 2.40 7810
40.0 3.21 1.04 × 104
50.0 4.01 1.30 × 104
60.0 4.81 1.56 × 104
70.0 5.61 1.82 × 104
80.0 6.41 2.08 × 104
90.0 7.21 2.34 × 104
99.8 8.00 2.60 × 104
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 3.06 6900
20.0 3.32 7500
30.0 4.99 1.13 × 104
40.0 6.65 1.50 × 104
48.1 8.00 1.80 × 104
Steel I Beam: S8 × 18.4 (S Section 8 inch tall × 18.4 lbf/ft)
L = 70.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
18.4 5.67 9390
20.0 6.16 1.02 × 104
26.0 8.00 1.33 × 104
Additional Information
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STEM Career Outlook

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

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.

CNC Machining Design Guide

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

more publications