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Glossary » Beams » Simply Supported » Uniformly Distributed Load » Four Equal Spans » S Section Steel I Beam » S6 × 12.5
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 = 22.1 in4) for the S6 × 12.5 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: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 3.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 1.64 × 10-5 19.6
20.0 2.62 × 10-5 31.4
30.0 3.93 × 10-5 47.1
40.0 5.24 × 10-5 62.8
50.0 6.55 × 10-5 78.5
60.0 7.86 × 10-5 94.2
70.0 9.17 × 10-5 110
80.0 1.05 × 10-4 126
90.0 1.18 × 10-4 141
100 1.31 × 10-4 157
200 2.62 × 10-4 314
300 3.93 × 10-4 471
400 5.24 × 10-4 628
500 6.55 × 10-4 785
600 7.86 × 10-4 942
700 9.17 × 10-4 1100
800 0.00105 1260
900 0.00118 1410
1000 0.00131 1570
2000 0.00262 3140
3000 0.00393 4710
4000 0.00524 6280
5000 0.00655 7850
6000 0.00786 9420
7000 0.00917 1.10 × 104
8000 0.0105 1.26 × 104
9000 0.0118 1.41 × 104
1.00 × 104 0.0131 1.57 × 104
2.00 × 104 0.0262 3.14 × 104
3.00 × 104 0.0393 4.71 × 104
4.00 × 104 0.0524 6.28 × 104
5.00 × 104 0.0655 7.85 × 104
6.00 × 104 0.0786 9.42 × 104
7.00 × 104 0.0917 1.10 × 105
8.00 × 104 0.105 1.26 × 105
9.00 × 104 0.118 1.41 × 105
1.00 × 105 0.131 1.57 × 105
1.89 × 105 0.248 2.97 × 105
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 5.00 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 1.26 × 10-4 54.5
20.0 2.02 × 10-4 87.2
30.0 3.03 × 10-4 131
40.0 4.04 × 10-4 174
50.0 5.05 × 10-4 218
60.0 6.06 × 10-4 262
70.0 7.08 × 10-4 305
80.0 8.09 × 10-4 349
90.0 9.10 × 10-4 393
100 0.00101 436
200 0.00202 872
300 0.00303 1310
400 0.00404 1740
500 0.00505 2180
600 0.00606 2620
700 0.00708 3050
800 0.00809 3490
900 0.00910 3930
1000 0.0101 4360
2000 0.0202 8720
3000 0.0303 1.31 × 104
4000 0.0404 1.74 × 104
5000 0.0505 2.18 × 104
6000 0.0606 2.62 × 104
7000 0.0708 3.05 × 104
8000 0.0809 3.49 × 104
9000 0.0910 3.93 × 104
1.00 × 104 0.101 4.36 × 104
2.00 × 104 0.202 8.72 × 104
3.00 × 104 0.303 1.31 × 105
4.00 × 104 0.404 1.74 × 105
5.00 × 104 0.505 2.18 × 105
6.00 × 104 0.606 2.62 × 105
6.81 × 104 0.688 2.97 × 105
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 10.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 0.00202 218
20.0 0.00323 349
30.0 0.00485 523
40.0 0.00647 698
50.0 0.00809 872
60.0 0.00970 1050
70.0 0.0113 1220
80.0 0.0129 1400
90.0 0.0146 1570
100 0.0162 1740
200 0.0323 3490
300 0.0485 5230
400 0.0647 6980
500 0.0809 8720
600 0.0970 1.05 × 104
700 0.113 1.22 × 104
800 0.129 1.40 × 104
900 0.146 1.57 × 104
1000 0.162 1.74 × 104
2000 0.323 3.49 × 104
3000 0.485 5.23 × 104
4000 0.647 6.98 × 104
5000 0.809 8.72 × 104
6000 0.970 1.05 × 105
7000 1.13 1.22 × 105
8000 1.29 1.40 × 105
9000 1.46 1.57 × 105
1.00 × 104 1.62 1.74 × 105
1.70 × 104 2.75 2.97 × 105
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 15.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 0.0102 491
20.0 0.0164 785
30.0 0.0246 1180
40.0 0.0328 1570
50.0 0.0409 1960
60.0 0.0491 2360
70.0 0.0573 2750
80.0 0.0655 3140
90.0 0.0737 3530
100 0.0819 3930
200 0.164 7850
300 0.246 1.18 × 104
400 0.328 1.57 × 104
500 0.409 1.96 × 104
600 0.491 2.36 × 104
700 0.573 2.75 × 104
800 0.655 3.14 × 104
900 0.737 3.53 × 104
1000 0.819 3.93 × 104
2000 1.64 7.85 × 104
3000 2.46 1.18 × 105
4000 3.28 1.57 × 105
5000 4.09 1.96 × 105
6000 4.91 2.36 × 105
7000 5.73 2.75 × 105
7570 6.20 2.97 × 105
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 20.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 0.0323 872
20.0 0.0518 1400
30.0 0.0776 2090
40.0 0.104 2790
50.0 0.129 3490
60.0 0.155 4190
70.0 0.181 4880
80.0 0.207 5580
90.0 0.233 6280
100 0.259 6980
200 0.518 1.40 × 104
300 0.776 2.09 × 104
400 1.04 2.79 × 104
500 1.29 3.49 × 104
600 1.55 4.19 × 104
700 1.81 4.88 × 104
800 2.07 5.58 × 104
900 2.33 6.28 × 104
1000 2.59 6.98 × 104
2000 5.18 1.40 × 105
2320 6.00 1.62 × 105
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 25.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 0.0790 1360
20.0 0.126 2180
30.0 0.190 3270
40.0 0.253 4360
50.0 0.316 5450
60.0 0.379 6540
70.0 0.442 7630
80.0 0.505 8720
90.0 0.569 9810
100 0.632 1.09 × 104
200 1.26 2.18 × 104
300 1.90 3.27 × 104
400 2.53 4.36 × 104
500 3.16 5.45 × 104
600 3.79 6.54 × 104
700 4.42 7.63 × 104
800 5.05 8.72 × 104
900 5.69 9.81 × 104
950 6.00 1.04 × 105
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 30.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 0.164 1960
20.0 0.262 3140
30.0 0.393 4710
40.0 0.524 6280
50.0 0.655 7850
60.0 0.786 9420
70.0 0.917 1.10 × 104
80.0 1.05 1.26 × 104
90.0 1.18 1.41 × 104
100 1.31 1.57 × 104
200 2.62 3.14 × 104
300 3.93 4.71 × 104
400 5.24 6.28 × 104
458 6.00 7.19 × 104
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 40.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 0.518 3490
20.0 0.828 5580
30.0 1.24 8370
40.0 1.66 1.12 × 104
50.0 2.07 1.40 × 104
60.0 2.48 1.67 × 104
70.0 2.90 1.95 × 104
80.0 3.31 2.23 × 104
90.0 3.73 2.51 × 104
100 4.14 2.79 × 104
145 6.00 4.05 × 104
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 50.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 1.26 5450
20.0 2.02 8720
30.0 3.03 1.31 × 104
40.0 4.04 1.74 × 104
50.0 5.05 2.18 × 104
59.4 6.00 2.59 × 104
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 60.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 2.62 7850
20.0 4.19 1.26 × 104
28.6 6.00 1.80 × 104
Steel I Beam: S6 × 12.5 (S6 inch tall × 12.5 lbf/ft)
L = 70.0 ft
P (lbf/ft) w_max (in) stress_max (psi)
12.5 4.85 1.07 × 104
15.5 6.00 1.32 × 104
Additional Information
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CNC Machining Design Guide

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

STEM Career Outlook

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

Essentials of Manufacturing

Information, coverage of important developments and expert commentary in manufacturing.

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Guide for high quality and cost-effective plastic injection molding.

more publications