Pipe description ++++++++++++++++++++++++++++++ Pipes are described by nominal size (e.g. 125A), which refers to and approximately matches inside diameter in mm. Pipe wall thickness is described by the pipe schedule (e.g. Schedule-40 or Schedule-80). Same A-size pipes in different schedules will have the same Outside Diameter (O.D.) but different wall thickness (Schedule-80 is thicker than Schedule-40). Schedules 5, 10, 20, 30, 40, 60, 80, 100, 120, 140, 160 JIS standard for steel ++++++++++++++++++++++++++++++ SUS 430 Stainless steel 18 Chrome SUS 304 Stainless steel 18 Chrome & 8 Nickel Example of steel pipe marking ++++++++++++++++++++++++++++++ JIS pipe categories +++++++++++++++++++++++++++++++ SGP Steel Gas Piping - Carbon Steel Pipe for Ordinary Piping STGP Steel Tube Piping General - Carbon Steel Pipe for pressure services STS Steel Tube Special - Carbon Steel Pipe for high pressure services STPT Steel Tube Piping Temperature - Carbon Steel Pipe for high temperature services STPL Steel Tube Piping Low - Carbon Steel Pipe for low temperature services Dimensions of Welded and Seamless Steel Pipe (ANSI/ASME B36.10M) | |||||||||
Nominal Pipe Size | Outside Diameter inch | Schedule 40 | Schedule 80 | Schedule 120 | Schedule 160 | ||||
inch | mm | inch | mm | inch | mm | inch | mm | ||
1/8 | 0.405 | 0.068 | 1.7 | 0.095 | 2.4 | ||||
1/4 | 0.540 | 0.088 | 2.2 | 0.119 | 3.0 | ||||
3/8 | 0.675 | 0.091 | 2.3 | 0.126 | 3.2 | ||||
1/2 | 0.840 | 0.109 | 2.8 | 0.147 | 3.7 | 0.188 | 4.8 | ||
3/4 | 1.050 | 0.113 | 2.9 | 0.154 | 3.9 | 0.219 | 5.6 | ||
1 | 1.315 | 0.133 | 3.4 | 0.179 | 4.5 | 0.250 | 6.4 | ||
1-1/4 | 1.660 | 0.140 | 3.6 | 0.191 | 4.9 | 0.250 | 6.4 | ||
1-1/2 | 1.900 | 0.145 | 3.7 | 0.200 | 5.1 | 0.281 | 7.1 | ||
2 | 2.375 | 0.154 | 3.9 | 0.218 | 5.5 | 0.344 | 8.7 | ||
2-1/2 | 2.875 | 0.203 | 5.2 | 0.276 | 7.0 | 0.375 | 9.5 | ||
3 | 3.500 | 0.216 | 5.5 | 0.300 | 7.6 | 0.438 | 11.1 | ||
3-1/2 | 4.000 | 0.226 | 5.7 | 0.318 | 8.1 | ||||
4 | 4.500 | 0.237 | 6.0 | 0.337 | 8.6 | 0.438 | 11.1 | 0.531 | 13.5 |
5 | 5.563 | 0.258 | 6.6 | 0.375 | 9.5 | 0.500 | 12.7 | 0.625 | 15.9 |
6 | 6.625 | 0.280 | 7.1 | 0.432 | 11.0 | 0.562 | 14.3 | 0.719 | 18.3 |
8 | 8.625 | 0.322 | 8.2 | 0.500 | 12.7 | 0.719 | 18.3 | 0.906 | 23.0 |
10 | 10.750 | 0.365 | 9.3 | 0.594 | 15.1 | 0.844 | 21.4 | 1.125 | 28.6 |
12 | 12.750 | 0.406 | 10.3 | 0.688 | 17.5 | 1.000 | 25.4 | 1.312 | 33.3 |
14 | 14.000 | 0.438 | 11.1 | 0.750 | 19.1 | 1.094 | 27.8 | 1.406 | 35.7 |
16 | 16.000 | 0.500 | 12.7 | 0.844 | 21.4 | 1.219 | 31.0 | 1.594 | 40.5 |
18 | 18.000 | 0.562 | 14.3 | 0.938 | 1.375 | 1.781 | |||
JIS ASTM Carbon Steel Pipe Outside Diameter Comparison and Actual Wall Thickness by Schedule Number
Nom. Size | Actual OD mm | Actual Wall Thickness by Schedule Numbers mm. | |||||||||||
A | B | JIS | ASTM | 10 | 20 | 30 | 40 | 60 | 80 | 100 | 120 | 140 | 160 |
6 | 1/8 | 10.5 | 10.3 | 1.7 | 2.2 | 2.4 | |||||||
8 | 1/4 | 13.8 | 13.7 | 2.2 | 2.4 | 3.0 | |||||||
10 | 3/8 | 17.3 | 17.1 | 2.3 | 2.8 | 3.2 | |||||||
15 | 1/2 | 21.7 | 21.3 | 2.8 | 3.2 | 3.7 | 4.7 | ||||||
20 | 3/4 | 27.2 | 26.7 | 2.9 | 3.4 | 3.9 | 5.5 | ||||||
25 | 1 | 34.0 | 33.4 | 3.4 | 3.9 | 4.5 | 6.4 | ||||||
32 | 1-1/4 | 42.7 | 42.2 | 3.6 | 4.5 | 4.9 | 6.4 | ||||||
40 | 1-1/2 | 48.6 | 48.3 | 3.7 | 4.5 | 5.1 | 7.1 | ||||||
50 | 2 | 60.5 | 60.3 | 3.2 | 3.9 | 4.9 | 5.5 | 8.7 | |||||
65 | 2-1/2 | 76.3 | 73.0 | 4.5 | 5.2 | 6.0 | 7.0 | 9.5 | |||||
80 | 3 | 89.1 | 88.9 | 4.5 | 5.5 | 6.6 | 7.6 | 11.1 | |||||
90 | 3-1/2 | 101.6 | 101.6 | 4.5 | 5.7 | 7.0 | 8.1 | 12.7 | |||||
100 | 4 | 114.3 | 114.3 | 4.9 | 6.0 | 7.1 | 8.6 | 11.1 | 13.5 | ||||
125 | 5 | 139.8 | 141.3 | 5.1 | 6.6 | 8.1 | 9.5 | 12.7 | 15.9 | ||||
150 | 6 | 165.2 | 168.3 | 5.5 | 7.1 | 9.3 | 11.0 | 14.3 | 18.2 | ||||
200 | 8 | 216.3 | 219.1 | 6.4 | 7.0 | 8.2 | 10.3 | 12.7 | 15.1 | 18.2 | 20.6 | 23.0 | |
250 | 10 | 267.4 | 273.1 | 6.4 | 7.8 | 9.3 | 12.7 | 15.1 | 18.2 | 21.4 | 25.4 | 28.6 | |
300 | 12 | 318.5 | 323.9 | 6.4 | 8.4 | 10.3 | 14.3 | 17.4 | 21.4 | 25.4 | 28.6 | . 33.3 | |
350 | 14 | 355.6 | 355.6 | 6.4 | 7.9 | 9.5 | 11.1 | 15.1 | 19.0 | 23.8 | 27.8 | 31.8 | 35.7 |
400 | 16 | 406.4 | 406.4 | 6.4 | 7.9 | 9.5 | 12.7 | 16.7 | 21.4 | 26.2 | 30.9 | 36.5 | 40.5 |
450 | 18 | 457.2 | 457.2 | 6.4 | 7.9 | 11.1 | 14.3 | 19.0 | 23.8 | 29.4 | 34.9 | 39.7 | 45.2 |
Symbol | Abbreviation | |
SGP | S: Steel G: Gas | P: Piping |
SGPW | S: Steel G: Gas | P: Piping W: Water |
STB | S: Steel T: Tube | B: Boiler |
STBA | S: Steel T: Tube | B: Boiler A: Alloy |
STBL | S: Steel T: Tube | B: Boiler L: Low Temperature |
STH | S: Steel T: Tube | H: High Pressure |
STK | S: Steel T: Tube | K: |
STKM | S: Steel T: Tube | K: M: Machine |
STKS | S: Steel T: Tube | K: S: Special |
STKR | S: Steel T: Tube | K: R: Rectangular |
STL | S: Steel T: Tube | L: Locomotive |
STM | S: Steel T: Tube | M: Mining |
C: Core or Casing R: Boring Rod | ||
STO | S: Steel T: Tube | O: Oil |
STPA | S: Steel T: Tube | P: Piping A: Alloy |
STPG | S: Steel T: Tube | P: Piping G: General |
STPL | S: Steel T: Tube | P: Piping L: Low |
STPT | S: Steel T: Tube | P: Piping T: Temperature |
STPY | S: Steel T: Tube | P: Piping Y: |
STS | S: Steel T: Tube | S: Special |
SUS-TP | S: Steel U: Use | S: Stainless T: Tube P: Piping |
SUS-TB | S: Steel U: Use | S: Stainless T: Tube B: Boiler |
