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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Two Equal Spans » S Section Steel I Beam » S20 × 66
S Section 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 = 1190 in4) for the S20 × 66 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
L = 150 ft
   
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 1.33 × 10-6 7.49
70.0 1.41 × 10-6 7.94
80.0 1.61 × 10-6 9.08
90.0 1.81 × 10-6 10.2
100 2.01 × 10-6 11.3
200 4.02 × 10-6 22.7
300 6.03 × 10-6 34.0
400 8.05 × 10-6 45.4
500 1.01 × 10-5 56.7
600 1.21 × 10-5 68.1
700 1.41 × 10-5 79.4
800 1.61 × 10-5 90.8
900 1.81 × 10-5 102
1000 2.01 × 10-5 113
2000 4.02 × 10-5 227
3000 6.03 × 10-5 340
4000 8.05 × 10-5 454
5000 1.01 × 10-4 567
6000 1.21 × 10-4 681
7000 1.41 × 10-4 794
8000 1.61 × 10-4 908
9000 1.81 × 10-4 1020
1.00 × 104 2.01 × 10-4 1130
2.00 × 104 4.02 × 10-4 2270
3.00 × 104 6.03 × 10-4 3400
4.00 × 104 8.05 × 10-4 4540
5.00 × 104 0.00101 5670
6.00 × 104 0.00121 6810
7.00 × 104 0.00141 7940
8.00 × 104 0.00161 9080
9.00 × 104 0.00181 1.02 × 104
1.00 × 105 0.00201 1.13 × 104
2.00 × 105 0.00402 2.27 × 104
3.00 × 105 0.00603 3.40 × 104
4.00 × 105 0.00805 4.54 × 104
5.00 × 105 0.0101 5.67 × 104
6.00 × 105 0.0121 6.81 × 104
7.00 × 105 0.0141 7.94 × 104
8.00 × 105 0.0161 9.08 × 104
9.00 × 105 0.0181 1.02 × 105
1.00 × 106 0.0201 1.13 × 105
2.00 × 106 0.0402 2.27 × 105
2.62 × 106 0.0527 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 1.02 × 10-5 20.8
70.0 1.09 × 10-5 22.1
80.0 1.24 × 10-5 25.2
90.0 1.40 × 10-5 28.4
100 1.55 × 10-5 31.5
200 3.10 × 10-5 63.0
300 4.66 × 10-5 94.5
400 6.21 × 10-5 126
500 7.76 × 10-5 158
600 9.31 × 10-5 189
700 1.09 × 10-4 221
800 1.24 × 10-4 252
900 1.40 × 10-4 284
1000 1.55 × 10-4 315
2000 3.10 × 10-4 630
3000 4.66 × 10-4 945
4000 6.21 × 10-4 1260
5000 7.76 × 10-4 1580
6000 9.31 × 10-4 1890
7000 0.00109 2210
8000 0.00124 2520
9000 0.00140 2840
1.00 × 104 0.00155 3150
2.00 × 104 0.00310 6300
3.00 × 104 0.00466 9450
4.00 × 104 0.00621 1.26 × 104
5.00 × 104 0.00776 1.58 × 104
6.00 × 104 0.00931 1.89 × 104
7.00 × 104 0.0109 2.21 × 104
8.00 × 104 0.0124 2.52 × 104
9.00 × 104 0.0140 2.84 × 104
1.00 × 105 0.0155 3.15 × 104
2.00 × 105 0.0310 6.30 × 104
3.00 × 105 0.0466 9.45 × 104
4.00 × 105 0.0621 1.26 × 105
5.00 × 105 0.0776 1.58 × 105
6.00 × 105 0.0931 1.89 × 105
7.00 × 105 0.109 2.21 × 105
8.00 × 105 0.124 2.52 × 105
9.00 × 105 0.140 2.84 × 105
9.43 × 105 0.146 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 1.64 × 10-4 83.2
70.0 1.74 × 10-4 88.2
80.0 1.99 × 10-4 101
90.0 2.23 × 10-4 113
100 2.48 × 10-4 126
200 4.97 × 10-4 252
300 7.45 × 10-4 378
400 9.93 × 10-4 504
500 0.00124 630
600 0.00149 756
700 0.00174 882
800 0.00199 1010
900 0.00223 1130
1000 0.00248 1260
2000 0.00497 2520
3000 0.00745 3780
4000 0.00993 5040
5000 0.0124 6300
6000 0.0149 7560
7000 0.0174 8820
8000 0.0199 1.01 × 104
9000 0.0223 1.13 × 104
1.00 × 104 0.0248 1.26 × 104
2.00 × 104 0.0497 2.52 × 104
3.00 × 104 0.0745 3.78 × 104
4.00 × 104 0.0993 5.04 × 104
5.00 × 104 0.124 6.30 × 104
6.00 × 104 0.149 7.56 × 104
7.00 × 104 0.174 8.82 × 104
8.00 × 104 0.199 1.01 × 105
9.00 × 104 0.223 1.13 × 105
1.00 × 105 0.248 1.26 × 105
2.00 × 105 0.497 2.52 × 105
2.36 × 105 0.585 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 8.30 × 10-4 187
70.0 8.80 × 10-4 199
80.0 0.00101 227
90.0 0.00113 255
100 0.00126 284
200 0.00251 567
300 0.00377 851
400 0.00503 1130
500 0.00629 1420
600 0.00754 1700
700 0.00880 1990
800 0.0101 2270
900 0.0113 2550
1000 0.0126 2840
2000 0.0251 5670
3000 0.0377 8510
4000 0.0503 1.13 × 104
5000 0.0629 1.42 × 104
6000 0.0754 1.70 × 104
7000 0.0880 1.99 × 104
8000 0.101 2.27 × 104
9000 0.113 2.55 × 104
1.00 × 104 0.126 2.84 × 104
2.00 × 104 0.251 5.67 × 104
3.00 × 104 0.377 8.51 × 104
4.00 × 104 0.503 1.13 × 105
5.00 × 104 0.629 1.42 × 105
6.00 × 104 0.754 1.70 × 105
7.00 × 104 0.880 1.99 × 105
8.00 × 104 1.01 2.27 × 105
9.00 × 104 1.13 2.55 × 105
1.00 × 105 1.26 2.84 × 105
1.05 × 105 1.32 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 0.00262 333
70.0 0.00278 353
80.0 0.00318 403
90.0 0.00358 454
100 0.00397 504
200 0.00795 1010
300 0.0119 1510
400 0.0159 2020
500 0.0199 2520
600 0.0238 3030
700 0.0278 3530
800 0.0318 4030
900 0.0358 4540
1000 0.0397 5040
2000 0.0795 1.01 × 104
3000 0.119 1.51 × 104
4000 0.159 2.02 × 104
5000 0.199 2.52 × 104
6000 0.238 3.03 × 104
7000 0.278 3.53 × 104
8000 0.318 4.03 × 104
9000 0.358 4.54 × 104
1.00 × 104 0.397 5.04 × 104
2.00 × 104 0.795 1.01 × 105
3.00 × 104 1.19 1.51 × 105
4.00 × 104 1.59 2.02 × 105
5.00 × 104 1.99 2.52 × 105
5.89 × 104 2.34 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 0.00640 520
70.0 0.00679 551
80.0 0.00776 630
90.0 0.00873 709
100 0.00970 788
200 0.0194 1580
300 0.0291 2360
400 0.0388 3150
500 0.0485 3940
600 0.0582 4730
700 0.0679 5510
800 0.0776 6300
900 0.0873 7090
1000 0.0970 7880
2000 0.194 1.58 × 104
3000 0.291 2.36 × 104
4000 0.388 3.15 × 104
5000 0.485 3.94 × 104
6000 0.582 4.73 × 104
7000 0.679 5.51 × 104
8000 0.776 6.30 × 104
9000 0.873 7.09 × 104
1.00 × 104 0.970 7.88 × 104
2.00 × 104 1.94 1.58 × 105
3.00 × 104 2.91 2.36 × 105
3.77 × 104 3.66 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 0.0133 749
70.0 0.0141 794
80.0 0.0161 908
90.0 0.0181 1020
100 0.0201 1130
200 0.0402 2270
300 0.0603 3400
400 0.0805 4540
500 0.101 5670
600 0.121 6810
700 0.141 7940
800 0.161 9080
900 0.181 1.02 × 104
1000 0.201 1.13 × 104
2000 0.402 2.27 × 104
3000 0.603 3.40 × 104
4000 0.805 4.54 × 104
5000 1.01 5.67 × 104
6000 1.21 6.81 × 104
7000 1.41 7.94 × 104
8000 1.61 9.08 × 104
9000 1.81 1.02 × 105
1.00 × 104 2.01 1.13 × 105
2.00 × 104 4.02 2.27 × 105
2.62 × 104 5.27 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 0.0420 1330
70.0 0.0445 1410
80.0 0.0509 1610
90.0 0.0572 1820
100 0.0636 2020
200 0.127 4030
300 0.191 6050
400 0.254 8070
500 0.318 1.01 × 104
600 0.381 1.21 × 104
700 0.445 1.41 × 104
800 0.509 1.61 × 104
900 0.572 1.82 × 104
1000 0.636 2.02 × 104
2000 1.27 4.03 × 104
3000 1.91 6.05 × 104
4000 2.54 8.07 × 104
5000 3.18 1.01 × 105
6000 3.81 1.21 × 105
7000 4.45 1.41 × 105
8000 5.09 1.61 × 105
9000 5.72 1.82 × 105
1.00 × 104 6.36 2.02 × 105
1.47 × 104 9.36 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 0.102 2080
70.0 0.109 2210
80.0 0.124 2520
90.0 0.140 2840
100 0.155 3150
200 0.310 6300
300 0.466 9450
400 0.621 1.26 × 104
500 0.776 1.58 × 104
600 0.931 1.89 × 104
700 1.09 2.21 × 104
800 1.24 2.52 × 104
900 1.40 2.84 × 104
1000 1.55 3.15 × 104
2000 3.10 6.30 × 104
3000 4.66 9.45 × 104
4000 6.21 1.26 × 105
5000 7.76 1.58 × 105
6000 9.31 1.89 × 105
7000 10.9 2.21 × 105
8000 12.4 2.52 × 105
9000 14.0 2.84 × 105
9430 14.6 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 0.212 2990
70.0 0.225 3180
80.0 0.257 3630
90.0 0.290 4080
100 0.322 4540
200 0.644 9080
300 0.965 1.36 × 104
400 1.29 1.82 × 104
500 1.61 2.27 × 104
600 1.93 2.72 × 104
700 2.25 3.18 × 104
800 2.57 3.63 × 104
900 2.90 4.08 × 104
1000 3.22 4.54 × 104
2000 6.44 9.08 × 104
3000 9.65 1.36 × 105
4000 12.9 1.82 × 105
5000 16.1 2.27 × 105
6000 19.3 2.72 × 105
6550 21.1 2.97 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 70.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 0.393 4080
70.0 0.417 4320
80.0 0.477 4940
90.0 0.537 5560
100 0.596 6180
200 1.19 1.24 × 104
300 1.79 1.85 × 104
400 2.38 2.47 × 104
500 2.98 3.09 × 104
600 3.58 3.71 × 104
700 4.17 4.32 × 104
800 4.77 4.94 × 104
900 5.37 5.56 × 104
1000 5.96 6.18 × 104
2000 11.9 1.24 × 105
3000 17.9 1.85 × 105
3350 20.0 2.07 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 80.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 0.671 5320
70.0 0.712 5650
80.0 0.814 6450
90.0 0.915 7260
100 1.02 8070
200 2.03 1.61 × 104
300 3.05 2.42 × 104
400 4.07 3.23 × 104
500 5.09 4.03 × 104
600 6.10 4.84 × 104
700 7.12 5.65 × 104
800 8.14 6.45 × 104
900 9.15 7.26 × 104
1000 10.2 8.07 × 104
1970 20.0 1.59 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 90.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 1.08 6740
70.0 1.14 7150
80.0 1.30 8170
90.0 1.47 9190
100 1.63 1.02 × 104
200 3.26 2.04 × 104
300 4.89 3.06 × 104
400 6.52 4.08 × 104
500 8.15 5.11 × 104
600 9.77 6.13 × 104
700 11.4 7.15 × 104
800 13.0 8.17 × 104
900 14.7 9.19 × 104
1000 16.3 1.02 × 105
1230 20.0 1.25 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 100 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 1.64 8320
70.0 1.74 8820
80.0 1.99 1.01 × 104
90.0 2.23 1.13 × 104
100 2.48 1.26 × 104
200 4.97 2.52 × 104
300 7.45 3.78 × 104
400 9.93 5.04 × 104
500 12.4 6.30 × 104
600 14.9 7.56 × 104
700 17.4 8.82 × 104
800 19.9 1.01 × 105
805 20.0 1.02 × 105
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 125 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 4.00 1.30 × 104
70.0 4.24 1.38 × 104
80.0 4.85 1.58 × 104
90.0 5.46 1.77 × 104
100 6.06 1.97 × 104
200 12.1 3.94 × 104
300 18.2 5.91 × 104
330 20.0 6.50 × 104
Steel I Beam: S20 × 66 (S20 inch tall × 66 lbf/ft)
L = 150 ft
P (lbf/ft) w_max (in) stress_max (psi)
66.0 8.30 1.87 × 104
70.0 8.80 1.99 × 104
80.0 10.1 2.27 × 104
90.0 11.3 2.55 × 104
100 12.6 2.84 × 104
159 20.0 4.51 × 104
Additional Information
Related Pages
FREE Publications
CNC Machining Design Guide

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

3D Scanners

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

Selecting the Right 3D Printer

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

STEM Career Outlook

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

more publications