Steel Pipe Specifications and Sizes: A Complete Chart

1. Steel Pipe Dimensions

An inch is divided into eight equal parts: 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8 inch.

These correspond to what is commonly referred to as 1/8 to 7/8 pipe sizes.

Smaller dimensions are represented by 1/16, 1/32, 1/64, with the unit still being inches. If the denominator and numerator can be reduced (e.g., when the numerator is 2, 4, 8, 16, 32), they should be.

The representation of an inch is marked with two prime symbols in the upper right corner, such as 1/2″.

For example, a DN25 (25mm and the same below) water pipe is equivalent to an imperial 1″ water pipe, which is also the former 8-part water pipe. A DN15 water pipe is equivalent to an imperial 1/2″ water pipe, which is also the former 4-part water pipe. A DN20 water pipe is equivalent to an imperial 3/4″ water pipe, which is also the former 6-part water pipe.

Dimensions: DN15 (4-part pipe), DN20 (6-part pipe), DN25 (1-inch pipe), DN32 (1 and 2-inch pipe), DN40 (1 and a half-inch pipe), DN50 (2-inch pipe), DN65 (2 and a half-inch pipe), DN80 (3-inch pipe), DN100 (4-inch pipe), DN125 (5-inch pipe), DN150 (6-inch pipe), DN200 (8-inch pipe), DN250 (10-inch pipe), and so on.

Steel pipe specifications have both imperial and international standards.

2. Steel Pipe Specifications and Models

mmmmmmcm2kg/mm2/mcm4cm3cm
30×23021.7591.3810.0941.7301.150.99
30×2.5302.52.1601.6950.0942.0601.370.98
34×23422.0111.5780.1072.5801.521.13
34×2.5342.52.4741.9420.1073.0901.821.12
38×23822.2621.7760.1193.6801.941.28
38×2.5382.52.7882.1890.1194.4102.321.26
38×33833.2992.5890.1195.0902.681.24
38×3.5383.53.7932.9780.1195.7003.001.23
40×24022.3881.8740.1264.3202.161.35
40×2.5402.52.9452.3120.1265.2002.601.33
42×24222.5131.9730.1325.0402.401.42
42×2.5422.53.1022.4350.1326.0702.891.40
42×34233.6762.8850.1327.0303.351.38
42×3.5423.54.2333.3230.1327.9103.771.37
42×44244.7753.7490.1328.7104.151.35
45×24522.7022.1210.1416.2602.781.52
45×2.5452.53.3382.6200.1417.5603.361.50
45×34533.9583.1070.1418.7703.901.49
45×3.5453.54.5633.5820.1419.8904.401.47
45×44545.1524.0440.14110.9304.861.46
50×2.5502.53.7312.9290.15710.5504.221.68
50×35034.4303.4770.15712.2804.911.67
50×3.5503.55.1134.0140.15713.9005.561.65
50×45045.7814.5380.15715.4106.161.63
50×4.5504.56.4325.0490.15716.8106.721.62
50×55057.0695.5490.15718.1107.241.60
51×25123.0792.4170.1609.2603.631.73
51×2.5512.53.8092.9900.16011.2304.401.72
51×35134.5243.5510.16013.0805.131.70
51×3.5513.55.2234.1000.16014.8105.811.68
54×25423.2672.5650.17011.0604.101.84
54×2.5542.54.0453.1750.17013.4404.981.82
54×35434.8073.7730.17015.6805.811.81
54×3.5543.55.5534.3590.17017.7906.591.79
54×45446.2834.9320.17019.7607.321.77
54×4.5544.56.9985.4930.17021.6108.001.76
54×55457.6976.0420.17023.3408.641.74
57×25723.4562.7130.17913.0804.591.95
57×2.5572.54.2803.3600.17915.9305.591.93
57×35735.0893.9950.17918.6106.531.91
57×3.5573.55.8834.6180.17921.1407.421.90
57×35735.0893.9950.17923.5208.252.15
57×4.5574.57.4225.8260.17925.7609.041.86
57×45746.6605.2280.17927.8609.782.05
57×5.5575.58.8996.9850.17929.84010.471.83
60×26023.6442.8610.18815.3405.112.05
60×2.5602.54.5163.5450.18818.7006.232.03
60×36035.3724.2170.18821.8807.292.02
60×3.5603.56.2124.8770.18824.8808.292.00
60×46047.0375.5240.18827.7309.241.99
60×4.5604.57.8466.1590.18830.41010.141.97
60×56058.6396.7820.18832.94010.981.95
60×5.5605.59.4177.3920.18835.32011.771.94
60×660610.1797.9900.18837.56012.521.92
63.5×26323.8333.0090.19818.2905.812.18
63.5×2.5632.54.7523.7300.19822.3207.092.17
63.5×36335.6554.4390.19826.1508.302.15
63.5×3.5633.56.5425.1360.19829.7909.462.13
63.5×46347.4145.8200.19833.24010.552.12
63.5×4.5634.58.2706.4920.19836.50011.592.10
63.5×56359.1117.1520.19839.60012.572.08
63.5×5.5635.59.9357.7990.19842.52013.502.07
63.5×663610.7448.4340.19845.28014.372.05
68×36836.1264.8090.21432.4209.542.30
68×3.5683.57.0925.5670.21436.99010.882.28
68×46848.0426.3130.21441.34012.162.27
68×4.5684.58.9777.0470.21445.47013.372.25
68×56859.8967.7680.21449.41014.532.23
68×5.5685.510.7998.4770.21453.14015.632.22
68×668611.6879.1740.21456.68016.672.20
70×27024.2733.3540.22024.7207.062.41
70×2.5702.55.3014.1620.22030.2308.642.39
70×37036.3154.9570.22035.50010.142.37
70×3.5703.57.3125.7400.22040.53011.582.35
70×47048.2946.5110.22045.33012.952.34
70×4.5704.59.2607.2690.22049.89014.252.32
70×570510.2108.0150.22054.24015.502.30
70×5.5705.511.1458.7490.22058.38016.682.29
70×670612.0649.4700.22062.31017.802.27
70×770713.85410.8760.22069.58019.882.24
73×37336.5975.1790.22940.48011.092.48
73×3.5733.57.6425.9990.22946.26012.672.46
73×47348.6716.8070.22951.78014.192.44
73×4.5734.59.6847.6020.22957.04015.632.43
73×573510.6818.3850.22962.07017.012.41
73×5.5735.511.6639.1560.22966.87018.322.39
73×673612.6299.9140.22971.43019.572.38
73×773714.51411.3940.22979.92021.902.35
76×27624.6503.6500.23931.8508.382.62
76×2.5762.55.7734.5320.23939.03010.272.60
76×37636.8805.4010.23945.91012.082.58
76×3.5763.57.9726.2580.23952.50013.822.57
76×47649.0487.1030.23958.81015.482.55
76×4.5764.510.1087.9350.23964.85017.072.53
76×576511.1538.7550.23970.62018.582.52
76×5.5765.512.1829.5620.23976.14020.042.50
76×676613.19510.3580.23981.41021.422.48
76×776715.17411.9120.23991.23024.012.45
83×28325.0893.9950.26141.76010.062.86
83×2.5832.56.3224.9630.26151.26012.352.85
83×38337.5405.9190.26160.40014.552.83
83×3.5833.58.7416.8620.26169.19016.672.81
83×48349.9277.7930.26177.64018.712.80
83×4.5834.511.0988.7120.26185.76020.672.78
83×583512.2529.6180.26193.56022.542.76
83×5.5835.513.39110.5120.261101.04024.352.75
83×683614.51411.3940.261108.22026.082.73
83×783716.71313.1200.261121.69029.322.70
83×883818.85014.7970.261134.04032.302.67
89×28925.4664.2910.28051.75011.633.08
89×2.5892.56.7945.3330.28063.59014.293.06
89×38938.1056.3630.28075.02016.863.04
89×3.5893.59.4017.3800.28086.05019.343.03
89×489410.6818.3850.28096.68021.733.01
89×4.5894.511.9469.3780.280106.92024.032.99
89×589513.19510.3580.280116.79026.242.98
89×5.5895.514.42811.3260.280126.29028.382.96
89×689615.64512.2810.280135.43030.432.94
89×789718.03314.1560.280152.67034.312.91
89×889820.35815.9810.280168.59037.892.88
95×29525.8434.5870.29863.20013.313.29
95×2.5952.57.2655.7030.29877.76016.373.27
95×39538.6716.8070.29891.83019.333.25
95×3.5953.510.0617.8980.298105.45022.203.24
95×495411.4358.9770.298118.60024.973.22
95×4.5954.512.79410.0430.298131.31027.643.20
95×595514.13711.0980.298143.58030.233.19
95×5.5955.515.46412.1400.298155.43032.723.17
95×695616.77613.1690.298166.86035.133.15
95×795719.35215.1910.298188.51039.693.12
95×895821.86517.1640.298208.62043.923.09
102×210226.2834.9320.32078.57015.413.54
102×2.51022.57.8156.1350.32096.77018.973.52
102×310239.3317.3240.320114.42022.443.50
102×3.51023.510.8318.5020.320131.52025.793.48
102×4102412.3159.6670.320148.09029.043.47
102×4.51024.513.78410.8200.320164.14032.183.45
102×5102515.23711.9610.320179.72035.243.43
102×5.51025.516.67413.0890.320194.72038.183.42
102×6102618.09614.2050.320209.28041.043.40
102×7102720.89216.4000.320236.96046.463.37
102×8102823.62518.5450.320262.83051.543.34
102×101021028.90322.6890.320309.40060.673.27
108×310839.8967.7680.339136.49025.283.71
108×3.51083.511.4909.0200.339157.02029.083.70
108×4108413.06910.2590.339176.95032.773.68
108×4.51084.514.63211.4860.339196.30036.353.66
108×5108516.17912.7010.339215.06039.833.65
108×5.51085.517.71113.9030.339233.26043.203.63
108×6108619.22715.0930.339250.91046.463.61
108×7108722.21117.4360.339284.58052.703.58
108×8108825.13319.7290.339316.17058.553.55
108×101081030.78824.1680.339373.45069.163.48
114×3114310.4628.2120.358161.24028.293.93
114×3.51143.512.1509.5380.358185.63032.573.91
114×4114413.82310.8510.358209.35036.733.89
114×4.51144.515.48012.1520.358232.41040.773.87
114×5114517.12213.4410.358254.81044.703.86
114×5.51145.518.74714.7170.358276.58048.523.84
114×6114620.35815.9810.358297.73052.233.82
114×7114413.82310.8510.358338.19059.334.95
114×8114826.64120.9130.358376.30066.023.76
114×101141032.67325.6480.358445.82078.213.69
121×3121311.1218.7300.380193.69032.014.17
121×3.51213.512.92010.1420.380223.17036.894.16
121×4121414.70311.5420.380251.87041.634.14
121×4.51214.516.47012.9290.380279.83046.254.12
121×5121518.22114.3040.380307.05050.754.11
121×5.51215.519.95715.6660.380333.54055.134.09
121×6121621.67717.0160.380359.32059.394.07
121×7121725.07019.6800.380408.80067.574.04
121×8121828.40022.2940.380455.57075.304.01
121×101211034.87227.3740.380541.43089.493.94
127×3127311.6879.1740.399224.75035.394.39
127×3.51273.513.58010.6600.399259.11040.804.37
127×4127415.45712.1330.399292.61046.084.35
127×4.51274.517.31813.5950.399325.29051.234.33
127×5127519.16415.0440.399357.14056.244.32
127×5.51275.520.99416.4800.399388.19061.134.30
127×6127622.80817.9040.399418.44065.904.28
127×7127726.38920.7160.399476.63075.064.25
127×8127829.90823.4780.399531.80083.754.22
127×101271036.75728.8540.399633.55099.774.15
127×121271243.35434.0330.399724.500114.094.09
133×4133416.21112.7250.418337.53050.764.56
133×4.51334.518.16614.2610.418375.42056.454.55
133×5133520.10615.7830.418412.40062.024.53
133×5.51335.522.03017.2940.418448.50067.444.51
133×6133623.93918.7920.418483.72072.744.50
133×7133727.70921.7510.418551.58082.944.46
133×8133831.41624.6620.418616.11092.654.43
133×101331038.64230.3340.418735.590110.624.36
133×121331245.61635.8090.418843.040126.774.30
140×4140417.09013.4160.440395.47056.504.81
140×4.51404.519.15615.0370.440440.12062.874.79
140×5140521.20616.6470.440483.76069.114.78
140×5.51405.523.24018.2430.440526.40075.204.76
140×6140625.25819.8280.440568.06081.154.74
140×7140729.24822.9600.440648.51092.644.71
140×8140833.17526.0430.440725.210103.604.68
140×101401040.84132.0600.440867.860123.984.61
140×121401248.25537.8800.440996.950142.424.55
140×141401455.41843.5030.4401113.340159.054.48
146×5146522.14817.3860.459551.10075.494.99
146×5.51465.524.27719.0570.459599.95082.184.97
146×6146626.38920.7160.459647.73088.734.95
146×7146730.56823.9960.459740.120101.394.92
146×8146834.68327.2260.459828.410113.484.89
146×101461042.72633.5400.459993.460136.094.82
146×121461250.51739.6560.4591142.940156.574.76
146×141461458.05745.5740.4591278.700175.164.69
152×5152523.09118.1260.478624.43082.165.20
152×5.51525.525.31319.8710.478680.06089.485.18
152×6152627.52021.6030.478734.52096.655.17
152×7152731.88725.0310.478839.990110.535.13
152×8152836.19128.4100.478940.970123.815.10
152×101521044.61135.0190.4781129.990148.685.03
152×121521252.77941.4310.4781302.580171.394.97
152×141521460.69647.6460.4781459.730192.074.90
159×5159524.19018.9890.500717.88090.305.45
159×6159628.84022.6390.500845.190106.315.41
159×7159733.42726.2400.500967.410121.695.38
159×8159837.95029.7910.5001084.670136.445.35
159×101591046.81036.7460.5001304.880164.145.28
159×121591255.41843.5030.5001506.880189.545.21
159×141591463.77450.0630.5001691.690212.795.15
168×5168525.60420.0990.528851.140101.335.77
168×6168630.53623.9710.5281003.120119.425.73
168×7168735.40627.7940.5281149.360136.835.70
168×8168840.21231.5670.5281290.010153.575.66
168×101681049.63738.9650.5281555.130185.135.60
168×121681258.81146.1660.5281799.600214.245.53
168×141681467.73353.1700.5282024.530241.025.47
168×161681676.40459.9770.5282230.980265.595.40
180×5180527.48921.5790.5651053.170117.026.19
180×6180632.79825.7470.5651242.720138.086.16
180×7180738.04529.8650.5651425.630158.406.12
180×8180843.22833.9340.5651602.040178.006.09
180×101801053.40741.9250.5651936.010215.116.02
180×121801263.33549.7180.5652245.840249.545.95
180×141801473.01157.3130.5652532.740281.425.89
180×161801682.43564.7120.5652797.860310.875.83
194×5194529.68823.3050.6091326.540136.766.68
194×6194635.43727.8180.6091567.210161.576.65
194×7194741.12332.2820.6091800.080185.586.62
194×8194846.74736.6960.6092025.310208.796.58
194×101941057.80545.3770.6092453.550252.946.51
194×121941268.61253.8610.6092853.250294.156.45
194×141941479.16862.1470.6093225.710332.556.38
194×161941689.47370.2360.6093572.190368.276.32
194×181941899.52678.1280.6093893.940401.446.25
203×6203637.13429.1500.6381803.070177.646.97
203×8203849.00938.4720.6382333.370229.896.90
203×102031060.63347.5970.6382830.720278.896.83
203×122031272.00556.5240.6383296.490324.786.77
203×142031483.12765.2540.6383732.070367.696.70
203×162031693.99673.7870.6384138.780407.766.64
203×1820318104.61582.1230.6384517.930445.126.57
219×6219640.15031.5170.6882278.740208.107.53
219×8219853.03041.6290.6882955.430269.907.47
219×102191065.65951.5430.6883593.290328.157.40
219×122191278.03761.2590.6884193.810383.007.33
219×142191490.16470.7790.6884758.500434.577.26
219×1621916102.03980.1010.6885288.810483.007.20
219×1821918113.66389.2250.6885786.150528.427.13
219×2021920125.03598.1530.6886251.930570.957.07
245×7245752.33941.0860.7703709.060302.788.42
245×8245859.56546.7580.7704186.870341.798.38
245×102451073.82757.9550.7705105.630416.798.32
245×122451287.83968.9540.7705976.670487.898.25
245×1424514101.59979.7550.7706801.680555.248.18
245×1624516115.10890.3600.7707582.300618.968.12
245×1824518128.365100.7670.7708320.170679.208.05
245×2024520141.372110.9770.7709016.860736.077.99
273×8273866.60252.2820.8585851.710428.709.37
273×102731082.62464.8600.8587154.090524.119.31
273×122731298.39577.2400.8588396.140615.109.24
273×1427314113.91489.4230.8588579.750628.558.68
273×1627316129.182101.4080.85810706.790784.389.10
273×1827318144.199113.1960.85811779.080862.949.04
273×2027320158.965124.7870.85812798.440937.618.97
299×8299873.13657.4120.9397747.420518.2210.29
299×102991090.79271.2720.9399490.150634.7910.22
299×1229912108.19684.9340.93911159.520746.4610.16
299×1429914125.35098.3990.93912757.610853.3510.09
299×1629916142.251111.6670.93914286.480955.6210.02
299×1829918158.902124.7380.93915748.1601053.399.96
299×2029920175.301137.6110.93917144.6401146.809.89

3. Steel Pipe Specifications and Dimensions

Nominal diameterInchesWelded pipeSeamless pipe
DN61 ∕810
DN81∕413.514
DN103 ∕81718
DN151∕221.2522
DN203∕426.7525
DN25133.532
DN321 1/442.2542
DN401 1/24848
DN5026057
DN652 1/275.574
DN803″88.589
DN1004″114108
DN1255″140133
DN1506″165159
DN1757″194194
DN2008″219219
DN2259″245245
DN25010″273273
DN30012″325325
DN35014″377377
DN40016″426426
DN45018″478478
DN50020″529529
DN60024″630630
DN70028″720720
DN80032″820820

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