Ultimate tensile strength or yield strength can be used. Ultimate should be used to determine the bursting pressure. Yield can be used for estimating pressures at which permanent deformation begins.

A chart is provided below that lists some minimum strength levels for guidance. Use of these values will yield conservative predictions relative to actual strength levels. For example, S31803: the minimum yield strength is 65,000 psi; the actual yield strength may (does) average 100,000 psi for RathGibson products.

From Machinery's Handbook 25 p. 268, and ASTM-A370 A2.3.4.

OD (in) (in)
Wall (in) (in)
Strength Factor (psi)
Safety Factor (working)  
Safety Factor (bursting) 1  
   
Theoretical Working
Pressure (selected SF)		 (psi)
Theoretical Bursting or
Yielding Pressure (SF=1)		 (psi)

Spec Minimum Requirements

OD (in)OD (mm)Wall (in)Wall (mm)GaugeBurst Pressure (psi)
1/8 (0.125) 3.2 0.020 0.51 25 24,000
    0.028 0.71 22 33,600
    0.035 0.89 20 42,000
3/16 (0.188) 4.8 0.020 0.51 25 16,000
    0.028 0.71 22 22,400
    0.035 0.89 20 28,000
1/4 (0.250) 6.4 0.020 0.51 25 12,000
    0.028 0.71 22 16,800
    0.035 0.89 20 21,000
    0.049 1.25 18 29,400
    0.065 1.65 16 39,000
    0.083 2.11 14 49,800
5/16 (0.313) 7.9 0.020 0.51 25 9,600
    0.028 0.71 22 13,440
    0.035 0.89 20 16,800
    0.049 1.25 18 23,520
    0.065 1.65 16 31,200
    0.083 2.11 14 39,840
3/8 (0.375) 9.5 0.020 0.51 25 8,000
    0.028 0.71 22 11,200
    0.035 0.89 20 14,000
    0.049 1.258 18 19,600
    0.065 1.65 16 26,000
    0.083 2.11 14 33,200
1/2 (0.500) 12.7 0.020 0.51 25 6,000
    0.028 0.71 22 8,400
    0.035 0.89 20 10,500
    0.049 1.25 18 14,700
    0.065 1.65 16 19,500
    0.083 2.11 14 24,900
    0.095 2.41 13 28,500
5/8 (0.625) 15.9 0.020 0.51 25 4,800
    0.028 0.71 33 6,720
    0.035 0.89 20 8,400
    0.049 1.25 18 11,760
    0.065 1.65 16 15,600
    0.083 2.11 14 19,920
    0.095 2.41 13 22,800
3/4 (0.750) 19.1 0.020 0.51 25 4,000
    0.028 0.71 22 5,600
    0.035 0.89 20 7,000
    0.049 1.25 18 9,800
    0.065 1.65 16 13,000
    0.083 2.11 14 16,600
    0.095 2.41 13 19,000
    0.109 2.77 12 21,800
7/8 (0.875) 22.2 0.020 0.51 25 3,429
    0.028 0.71 22 4,800
    0.035 0.89 20 6,000
    0.049 1.25 18 8,400
    0.065 1.65 16 11,143
    0.083 2.11 14 14,229
    0.095 2.41 13 16,286
    0.109 2.77 12 18,686
1 (1.000) 25.4 0.020 0.51 25 3,000
    0.028 0.71 22 4,200
    0.035 0.89 20 5,250
    0.049 1.25 18 7,350
    0.065 1.65 16 9,750
    0.083 2.11 14 12,450
    0.095 2.41 13 14,250
    0.109 2.77 12 16,350
    0.120 3.05 11 18,000
1-1/8 (1.125) 28.6 0.028 0.71 22 3,733
    0.035 0.89 20 4,667
    0.049 1.25 18 6,533
    0.065 1.65 16 8,667
    0.083 2.11 14 11,067
    0.095 2.41 13 12,667
    0.109 2.77 12 14,533
    0.120 3.05 11 16,000
1-1/4 (1.250) 31.8 0.028 0.71 22 3,360
    0.035 0.89 20 4,200
    0.049 1.25 18 5,880
    0.065 1.65 16 7,800
    0.083 2.11 14 9,960
    0.095 2.41 13 11,400
    0.109 2.77 12 13,080
    0.120 3.05 11 14,400
1-3/8 (1.375) 34.9 0.035 0.89 20 3,818
    0.049 1.25 18 5,345
    0.065 1.65 16 7,091
    0.083 2.11 14 9,055
    0.095 2.41 13 10,364
    0.109 2.77 12 11,891
    0.120 3.05 11 13,091
1-1/2 (1.500) 38.1 0.035 0.49 20 3,500
    0.049 1.25 18 4,900
    0.065 1.65 16 6,500
    0.083 2.11 14 8,300
    0.095 2.41 13 9,500
    0.109 2.77 12 10,900
    0.120 3.05 11 12,000
1-5/8 (1.625) 41.3 0.035 0.49 20 3,229
    0.049 1.25 18 4,520
    0.065 1.65 16 5,996
    0.083 2.11 14 7,657
    0.095 2.41 13 8,764
    0.109 2.77 12 10,055
    0.120 3.05 11 11,070
1-3/4 (1.750) 44.5 0.035 0.89 20 3,000
    0.049 1.25 18 4,200
    0.065 1.65 16 5,571
    0.083 2.11 14 7,114
    0.095 2.41 13 8,143
    0.109 2.77 12 9,343
    0.120 3.05 111 10,286
2 (2.000) 50.8 0.035 0.89 20 2,625
    0.049 1.25 18 3,675
    0.065 1.65 16 4,875
    0.083 2.11 14 6,225
    0.095 2.41 13 7,125
    0.109 2.77 12 8,175
    0.120 3.05 11 9,000
2-1/8 (2.125) 54.0 0.049 1.25 18 3,459
    0.065 1.65 16 4,588
    0.083 2.11 14 5,859
    0.095 2.41 13 6,706
    0.109 2.77 12 7,694
    0.120 3.05 11 8,471
2-1/4 (2.250) 57.2 0.049 1.25 18 3,267
    0.065 1.65 16 4,333
    0.083 2.11 14 5,533
    0.095 2.41 13 6,333
    0.109 2.77 12 7,267
    0.120 3.05 11 8,000
2-1/2 (2.500) 63.5 0.049 1.25 18 2,940
    0.065 1.65 16 3,900
    0.083 2.11 14 4,980
    0.095 2.41 13 5,700
    0.109 2.77 12 6,540
    0.120 3.05 11 7,200
2-5/8 (2.625) 66.7 0.049 1.25 18 2,800
    0.065 1.65 16 3,714
    0.083 2.11 14 4,743
    0.095 2.41 13 5,429
    0.109 2.77 12 6,229
    0.120 3.05 11 6,857
2-3/4 (2.750) 69.9 0.049 1.25 18 2,673
    0.065 1.65 16 3,545
    0.083 2.11 14 4,527
    0.095 2.41 13 5,182
    0.109 2.77 12 5,945
    0.120 3.05 11 6,545
3 (3.000) 76.2 0.049 1.25 18 2,450
    0.065 1.65 16 3,250
    0.083 2.11 14 4,527
    0.095 2.41 13 4,750
    0.109 2.77 12 5,450
    0.120 3.05 11 6,000
3-1/2 (3.500) 88.9 0.065 1.65 16 2,786
    0.083 2.11 14 3,557
    0.095 2.41 13 4,071
    0.109 2.77 12 4,671
    0.120 3.05 11 5,143
4 (4.000) 101.6 0.065 1.65 16 2,438
    0.083 2.11 14 3,113
    0.095 2.41 13 3,563
    0.109 2.77 12 4,088
    0.120 3.05 11 4,500
6 (6.000) 152.4 0.083 2.11   2,100
    0.109 2.77   2,700
8 (8.000) 203.2 0.109 2.77   2,000