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 free publications

Materials

Design

Processes

Units

Formulas

Math
Glossary » Beams » Simply Supported » Uniformly Distributed Load » Four Equal Spans » S Section Steel I Beam » S12 × 50
S Section Steel I Beam | Single Span | Two Equal Spans | Three Equal Spans | Four Equal Spans

For a simply supported beam in four equal spans, we compute the displacement at the middle of the first and fourth spans, and the maximum normal stress stress_max occuring at the second and fourth supports of the beam.
The tabulated data listed in this page are calculated based on the area moment of inertia (Ixx = 305 in4) for the S12 × 50 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
   
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 4.75 × 10-6 11.4
60.0 5.70 × 10-6 13.7
70.0 6.64 × 10-6 15.9
80.0 7.59 × 10-6 18.2
90.0 8.54 × 10-6 20.5
100 9.49 × 10-6 22.8
200 1.90 × 10-5 45.5
300 2.85 × 10-5 68.3
400 3.80 × 10-5 91.0
500 4.75 × 10-5 114
600 5.70 × 10-5 137
700 6.64 × 10-5 159
800 7.59 × 10-5 182
900 8.54 × 10-5 205
1000 9.49 × 10-5 228
2000 1.90 × 10-4 455
3000 2.85 × 10-4 683
4000 3.80 × 10-4 910
5000 4.75 × 10-4 1140
6000 5.70 × 10-4 1370
7000 6.64 × 10-4 1590
8000 7.59 × 10-4 1820
9000 8.54 × 10-4 2050
1.00 × 104 9.49 × 10-4 2280
2.00 × 104 0.00190 4550
3.00 × 104 0.00285 6830
4.00 × 104 0.00380 9100
5.00 × 104 0.00475 1.14 × 104
6.00 × 104 0.00570 1.37 × 104
7.00 × 104 0.00664 1.59 × 104
8.00 × 104 0.00759 1.82 × 104
9.00 × 104 0.00854 2.05 × 104
1.00 × 105 0.00949 2.28 × 104
2.00 × 105 0.0190 4.55 × 104
3.00 × 105 0.0285 6.83 × 104
4.00 × 105 0.0380 9.10 × 104
5.00 × 105 0.0475 1.14 × 105
6.00 × 105 0.0570 1.37 × 105
7.00 × 105 0.0664 1.59 × 105
8.00 × 105 0.0759 1.82 × 105
9.00 × 105 0.0854 2.05 × 105
1.00 × 106 0.0949 2.28 × 105
1.31 × 106 0.124 2.97 × 105
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 3.66 × 10-5 31.6
60.0 4.39 × 10-5 37.9
70.0 5.13 × 10-5 44.2
80.0 5.86 × 10-5 50.6
90.0 6.59 × 10-5 56.9
100 7.32 × 10-5 63.2
200 1.46 × 10-4 126
300 2.20 × 10-4 190
400 2.93 × 10-4 253
500 3.66 × 10-4 316
600 4.39 × 10-4 379
700 5.13 × 10-4 442
800 5.86 × 10-4 506
900 6.59 × 10-4 569
1000 7.32 × 10-4 632
2000 0.00146 1260
3000 0.00220 1900
4000 0.00293 2530
5000 0.00366 3160
6000 0.00439 3790
7000 0.00513 4420
8000 0.00586 5060
9000 0.00659 5690
1.00 × 104 0.00732 6320
2.00 × 104 0.0146 1.26 × 104
3.00 × 104 0.0220 1.90 × 104
4.00 × 104 0.0293 2.53 × 104
5.00 × 104 0.0366 3.16 × 104
6.00 × 104 0.0439 3.79 × 104
7.00 × 104 0.0513 4.42 × 104
8.00 × 104 0.0586 5.06 × 104
9.00 × 104 0.0659 5.69 × 104
1.00 × 105 0.0732 6.32 × 104
2.00 × 105 0.146 1.26 × 105
3.00 × 105 0.220 1.90 × 105
4.00 × 105 0.293 2.53 × 105
4.70 × 105 0.344 2.97 × 105
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 5.86 × 10-4 126
60.0 7.03 × 10-4 152
70.0 8.20 × 10-4 177
80.0 9.38 × 10-4 202
90.0 0.00105 228
100 0.00117 253
200 0.00234 506
300 0.00352 758
400 0.00469 1010
500 0.00586 1260
600 0.00703 1520
700 0.00820 1770
800 0.00938 2020
900 0.0105 2280
1000 0.0117 2530
2000 0.0234 5060
3000 0.0352 7580
4000 0.0469 1.01 × 104
5000 0.0586 1.26 × 104
6000 0.0703 1.52 × 104
7000 0.0820 1.77 × 104
8000 0.0938 2.02 × 104
9000 0.105 2.28 × 104
1.00 × 104 0.117 2.53 × 104
2.00 × 104 0.234 5.06 × 104
3.00 × 104 0.352 7.58 × 104
4.00 × 104 0.469 1.01 × 105
5.00 × 104 0.586 1.26 × 105
6.00 × 104 0.703 1.52 × 105
7.00 × 104 0.820 1.77 × 105
8.00 × 104 0.938 2.02 × 105
9.00 × 104 1.05 2.28 × 105
1.00 × 105 1.17 2.53 × 105
1.17 × 105 1.38 2.97 × 105
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 0.00297 284
60.0 0.00356 341
70.0 0.00415 398
80.0 0.00475 455
90.0 0.00534 512
100 0.00593 569
200 0.0119 1140
300 0.0178 1710
400 0.0237 2280
500 0.0297 2840
600 0.0356 3410
700 0.0415 3980
800 0.0475 4550
900 0.0534 5120
1000 0.0593 5690
2000 0.119 1.14 × 104
3000 0.178 1.71 × 104
4000 0.237 2.28 × 104
5000 0.297 2.84 × 104
6000 0.356 3.41 × 104
7000 0.415 3.98 × 104
8000 0.475 4.55 × 104
9000 0.534 5.12 × 104
1.00 × 104 0.593 5.69 × 104
2.00 × 104 1.19 1.14 × 105
3.00 × 104 1.78 1.71 × 105
4.00 × 104 2.37 2.28 × 105
5.00 × 104 2.97 2.84 × 105
5.22 × 104 3.10 2.97 × 105
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 0.00938 506
60.0 0.0113 607
70.0 0.0131 708
80.0 0.0150 809
90.0 0.0169 910
100 0.0188 1010
200 0.0375 2020
300 0.0563 3030
400 0.0750 4050
500 0.0938 5060
600 0.113 6070
700 0.131 7080
800 0.150 8090
900 0.169 9100
1000 0.188 1.01 × 104
2000 0.375 2.02 × 104
3000 0.563 3.03 × 104
4000 0.750 4.05 × 104
5000 0.938 5.06 × 104
6000 1.13 6.07 × 104
7000 1.31 7.08 × 104
8000 1.50 8.09 × 104
9000 1.69 9.10 × 104
1.00 × 104 1.88 1.01 × 105
2.00 × 104 3.75 2.02 × 105
2.94 × 104 5.51 2.97 × 105
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 0.0229 790
60.0 0.0275 948
70.0 0.0320 1110
80.0 0.0366 1260
90.0 0.0412 1420
100 0.0458 1580
200 0.0916 3160
300 0.137 4740
400 0.183 6320
500 0.229 7900
600 0.275 9480
700 0.320 1.11 × 104
800 0.366 1.26 × 104
900 0.412 1.42 × 104
1000 0.458 1.58 × 104
2000 0.916 3.16 × 104
3000 1.37 4.74 × 104
4000 1.83 6.32 × 104
5000 2.29 7.90 × 104
6000 2.75 9.48 × 104
7000 3.20 1.11 × 105
8000 3.66 1.26 × 105
9000 4.12 1.42 × 105
1.00 × 104 4.58 1.58 × 105
1.88 × 104 8.61 2.97 × 105
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 0.0475 1140
60.0 0.0570 1370
70.0 0.0664 1590
80.0 0.0759 1820
90.0 0.0854 2050
100 0.0949 2280
200 0.190 4550
300 0.285 6830
400 0.380 9100
500 0.475 1.14 × 104
600 0.570 1.37 × 104
700 0.664 1.59 × 104
800 0.759 1.82 × 104
900 0.854 2.05 × 104
1000 0.949 2.28 × 104
2000 1.90 4.55 × 104
3000 2.85 6.83 × 104
4000 3.80 9.10 × 104
5000 4.75 1.14 × 105
6000 5.70 1.37 × 105
7000 6.64 1.59 × 105
8000 7.59 1.82 × 105
9000 8.54 2.05 × 105
1.00 × 104 9.49 2.28 × 105
1.31 × 104 12.4 2.97 × 105
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 0.150 2020
60.0 0.180 2430
70.0 0.210 2830
80.0 0.240 3240
90.0 0.270 3640
100 0.300 4050
200 0.600 8090
300 0.900 1.21 × 104
400 1.20 1.62 × 104
500 1.50 2.02 × 104
600 1.80 2.43 × 104
700 2.10 2.83 × 104
800 2.40 3.24 × 104
900 2.70 3.64 × 104
1000 3.00 4.05 × 104
2000 6.00 8.09 × 104
3000 9.00 1.21 × 105
4000 12.0 1.62 × 105
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 0.366 3160
60.0 0.439 3790
70.0 0.513 4420
80.0 0.586 5060
90.0 0.659 5690
100 0.732 6320
200 1.46 1.26 × 104
300 2.20 1.90 × 104
400 2.93 2.53 × 104
500 3.66 3.16 × 104
600 4.39 3.79 × 104
700 5.13 4.42 × 104
800 5.86 5.06 × 104
900 6.59 5.69 × 104
1000 7.32 6.32 × 104
1640 12.0 1.04 × 105
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 0.759 4550
60.0 0.911 5460
70.0 1.06 6370
80.0 1.22 7280
90.0 1.37 8190
100 1.52 9100
200 3.04 1.82 × 104
300 4.56 2.73 × 104
400 6.08 3.64 × 104
500 7.59 4.55 × 104
600 9.11 5.46 × 104
700 10.6 6.37 × 104
790 12.0 7.19 × 104
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 70.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 1.41 6190
60.0 1.69 7430
70.0 1.97 8670
80.0 2.25 9910
90.0 2.53 1.11 × 104
100 2.81 1.24 × 104
200 5.63 2.48 × 104
300 8.44 3.72 × 104
400 11.3 4.96 × 104
426 12.0 5.28 × 104
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 80.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 2.40 8090
60.0 2.88 9710
70.0 3.36 1.13 × 104
80.0 3.84 1.29 × 104
90.0 4.32 1.46 × 104
100 4.80 1.62 × 104
200 9.60 3.24 × 104
250 12.0 4.05 × 104
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 90.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 3.84 1.02 × 104
60.0 4.61 1.23 × 104
70.0 5.38 1.43 × 104
80.0 6.15 1.64 × 104
90.0 6.92 1.84 × 104
100 7.69 2.05 × 104
156 12.0 3.20 × 104
Steel I Beam: S12 × 50 (S12 inch tall × 50 lbf/ft)
L = 100 ft
P (lbf/ft) w_max (in) stress_max (psi)
50.0 5.86 1.26 × 104
60.0 7.03 1.52 × 104
70.0 8.20 1.77 × 104
80.0 9.38 2.02 × 104
90.0 10.5 2.28 × 104
100 11.7 2.53 × 104
102 12.0 2.59 × 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