Negotiate Your Salary

Learn the best principles to negotiate the salary you deserve!

Mechanical Engineers Outlook

Guide for those interested in becoming a mechanical engineer. Includes qualifications, pay, and job duties.

STEM Career Outlook

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

Metal 3D Printing Design Guide

Direct Metal Laser Sintering (DMLS) 3D printing for parts with reduced cost and little waste.

more free publications

Materials

Design

Processes

Units

Formulas

Math
Glossary » Beams » Simply Supported » Uniformly Distributed Load » Two 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 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 = 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 1.35 × 10-5 22.9
20.0 2.17 × 10-5 36.7
30.0 3.25 × 10-5 55.0
40.0 4.33 × 10-5 73.3
50.0 5.42 × 10-5 91.6
60.0 6.50 × 10-5 110
70.0 7.58 × 10-5 128
80.0 8.66 × 10-5 147
90.0 9.75 × 10-5 165
100 1.08 × 10-4 183
200 2.17 × 10-4 367
300 3.25 × 10-4 550
400 4.33 × 10-4 733
500 5.42 × 10-4 916
600 6.50 × 10-4 1100
700 7.58 × 10-4 1280
800 8.66 × 10-4 1470
900 9.75 × 10-4 1650
1000 0.00108 1830
2000 0.00217 3670
3000 0.00325 5500
4000 0.00433 7330
5000 0.00542 9160
6000 0.00650 1.10 × 104
7000 0.00758 1.28 × 104
8000 0.00866 1.47 × 104
9000 0.00975 1.65 × 104
1.00 × 104 0.0108 1.83 × 104
2.00 × 104 0.0217 3.67 × 104
3.00 × 104 0.0325 5.50 × 104
4.00 × 104 0.0433 7.33 × 104
5.00 × 104 0.0542 9.16 × 104
6.00 × 104 0.0650 1.10 × 105
7.00 × 104 0.0758 1.28 × 105
8.00 × 104 0.0866 1.47 × 105
9.00 × 104 0.0975 1.65 × 105
1.00 × 105 0.108 1.83 × 105
1.62 × 105 0.176 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 1.04 × 10-4 63.6
20.0 1.67 × 10-4 102
30.0 2.51 × 10-4 153
40.0 3.34 × 10-4 204
50.0 4.18 × 10-4 255
60.0 5.01 × 10-4 305
70.0 5.85 × 10-4 356
80.0 6.69 × 10-4 407
90.0 7.52 × 10-4 458
100 8.36 × 10-4 509
200 0.00167 1020
300 0.00251 1530
400 0.00334 2040
500 0.00418 2550
600 0.00501 3050
700 0.00585 3560
800 0.00669 4070
900 0.00752 4580
1000 0.00836 5090
2000 0.0167 1.02 × 104
3000 0.0251 1.53 × 104
4000 0.0334 2.04 × 104
5000 0.0418 2.55 × 104
6000 0.0501 3.05 × 104
7000 0.0585 3.56 × 104
8000 0.0669 4.07 × 104
9000 0.0752 4.58 × 104
1.00 × 104 0.0836 5.09 × 104
2.00 × 104 0.167 1.02 × 105
3.00 × 104 0.251 1.53 × 105
4.00 × 104 0.334 2.04 × 105
5.00 × 104 0.418 2.55 × 105
5.84 × 104 0.488 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 0.00167 255
20.0 0.00267 407
30.0 0.00401 611
40.0 0.00535 814
50.0 0.00669 1020
60.0 0.00802 1220
70.0 0.00936 1430
80.0 0.0107 1630
90.0 0.0120 1830
100 0.0134 2040
200 0.0267 4070
300 0.0401 6110
400 0.0535 8140
500 0.0669 1.02 × 104
600 0.0802 1.22 × 104
700 0.0936 1.43 × 104
800 0.107 1.63 × 104
900 0.120 1.83 × 104
1000 0.134 2.04 × 104
2000 0.267 4.07 × 104
3000 0.401 6.11 × 104
4000 0.535 8.14 × 104
5000 0.669 1.02 × 105
6000 0.802 1.22 × 105
7000 0.936 1.43 × 105
8000 1.07 1.63 × 105
9000 1.20 1.83 × 105
1.00 × 104 1.34 2.04 × 105
1.46 × 104 1.95 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 0.00846 573
20.0 0.0135 916
30.0 0.0203 1370
40.0 0.0271 1830
50.0 0.0338 2290
60.0 0.0406 2750
70.0 0.0474 3210
80.0 0.0542 3670
90.0 0.0609 4120
100 0.0677 4580
200 0.135 9160
300 0.203 1.37 × 104
400 0.271 1.83 × 104
500 0.338 2.29 × 104
600 0.406 2.75 × 104
700 0.474 3.21 × 104
800 0.542 3.67 × 104
900 0.609 4.12 × 104
1000 0.677 4.58 × 104
2000 1.35 9.16 × 104
3000 2.03 1.37 × 105
4000 2.71 1.83 × 105
5000 3.38 2.29 × 105
6000 4.06 2.75 × 105
6480 4.39 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 0.0267 1020
20.0 0.0428 1630
30.0 0.0642 2440
40.0 0.0856 3260
50.0 0.107 4070
60.0 0.128 4890
70.0 0.150 5700
80.0 0.171 6520
90.0 0.193 7330
100 0.214 8140
200 0.428 1.63 × 104
300 0.642 2.44 × 104
400 0.856 3.26 × 104
500 1.07 4.07 × 104
600 1.28 4.89 × 104
700 1.50 5.70 × 104
800 1.71 6.52 × 104
900 1.93 7.33 × 104
1000 2.14 8.14 × 104
2000 4.28 1.63 × 105
2800 6.00 2.28 × 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 0.0653 1590
20.0 0.104 2550
30.0 0.157 3820
40.0 0.209 5090
50.0 0.261 6360
60.0 0.313 7640
70.0 0.366 8910
80.0 0.418 1.02 × 104
90.0 0.470 1.15 × 104
100 0.522 1.27 × 104
200 1.04 2.55 × 104
300 1.57 3.82 × 104
400 2.09 5.09 × 104
500 2.61 6.36 × 104
600 3.13 7.64 × 104
700 3.66 8.91 × 104
800 4.18 1.02 × 105
900 4.70 1.15 × 105
1000 5.22 1.27 × 105
1150 6.00 1.46 × 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 0.135 2290
20.0 0.217 3670
30.0 0.325 5500
40.0 0.433 7330
50.0 0.542 9160
60.0 0.650 1.10 × 104
70.0 0.758 1.28 × 104
80.0 0.866 1.47 × 104
90.0 0.975 1.65 × 104
100 1.08 1.83 × 104
200 2.17 3.67 × 104
300 3.25 5.50 × 104
400 4.33 7.33 × 104
500 5.42 9.16 × 104
554 6.00 1.02 × 105
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 0.428 4070
20.0 0.685 6520
30.0 1.03 9770
40.0 1.37 1.30 × 104
50.0 1.71 1.63 × 104
60.0 2.05 1.95 × 104
70.0 2.40 2.28 × 104
80.0 2.74 2.61 × 104
90.0 3.08 2.93 × 104
100 3.42 3.26 × 104
175 6.00 5.71 × 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 1.04 6360
20.0 1.67 1.02 × 104
30.0 2.51 1.53 × 104
40.0 3.34 2.04 × 104
50.0 4.18 2.55 × 104
60.0 5.01 3.05 × 104
70.0 5.85 3.56 × 104
71.8 6.00 3.65 × 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 2.17 9160
20.0 3.47 1.47 × 104
30.0 5.20 2.20 × 104
34.6 6.00 2.54 × 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 4.01 1.25 × 104
18.7 6.00 1.86 × 104
Additional Information
Related Pages
Glossary
FREE Publications
Negotiate Your Salary

Learn the best principles to negotiate the salary you deserve!

Mechanical Engineers Outlook

Guide for those interested in becoming a mechanical engineer. Includes qualifications, pay, and job duties.

STEM Career Outlook

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

Metal 3D Printing Design Guide

Direct Metal Laser Sintering (DMLS) 3D printing for parts with reduced cost and little waste.

more publications