Stainless steel tubing is a fantastic material that is used in a variety of construction projects, be it industrial or domestic. Stainless steel tube is widely used in industrial industries, where the sizes and variations available vary based on the fabrication project.
Stainless steel is remarkable for builders and manufacturers in many industries and is renowned for corrosion resistance, strength, and low maintenance. The structural applications of stainless steel tubing need precise sizing based on the OD (Outside Diameter) and WT (Weight) (Wall Thickness).
There are many stainless steel grades of tubing in use for hypodermic, fractional, metric, or square tubing is determined by the application’s specific needs and specifications, such as food processing or medical.
In our guide, you can learn more about finding the correct stainless steel tube dimensions. By the end, you can use one of our charts to find the wall thicknesses, outer diameter, and inner diameter or any custom size of tubing you desire. (Read Angle Steel Sizes Chart)
What sizes does stainless steel pipe come in?
Steel is an alloy made up of iron and carbon. Stainless steel is “stainless” (corrosion resistant) and gets its name from a minimum of 10.5 percent chromium content by mass.
The addition of other alloys determines the many grades, or variants, of stainless.
Stainless steel may also contain components like silicon, nickel, titanium, aluminum, copper, molybdenum, and enhanced chromium levels, among others depending on the use such as medical, chemical, or the fabrication of heat exchangers.
Grade 316 stainless steel, for example, contains higher molybdenum levels in the overall composition to improve the material’s corrosion resistance and strength at high temperatures. Heat exchangers and automobile exhaust systems are among Grade 316 stainless steel applications.
| Stainless Steel Tubing Dimensions | Size OD, Inches | BW Ga. | Wall Dec-In. | ID | Weight Lbs/Ft. |
|---|---|---|---|---|---|
| Stainless steel tubing dimensions | 1/8 | 22 | 0.028 | 0.069 | 0.0290 |
| 20 | 0.035 | 0.055 | 0.0336 | ||
| Stainless steel tubing dimensions | 3/16 | 22 | 0.028 | 0.131 | 0.0478 |
| Stainless steel tubing dimensions | 1/4 | 25 | 0.020 | 0.210 | 0.0491 |
| 22 | 0.028 | 0.194 | 0.0664 | ||
| 21 | 0.032 | 0.187 | 0.0745 | ||
| 20 | 0.035 | 0.180 | 0.0804 | ||
| 18 | 0.049 | 0.152 | 0.1052 | ||
| 16 | 0.065 | 0.120 | 0.1284 | ||
| Stainless steel tubing dimensions | 5/16 | 20 | 0.035 | 0.242 | 0.1039 |
| 18 | 0.049 | 0.214 | 0.1382 | ||
| 16 | 0.065 | 0.182 | 0.1722 | ||
| Stainless steel tubing dimensions | 3/8 | 20 | 0.035 | 0.305 | 0.1271 |
| 18 | 0.049 | 0.277 | 0.1706 | ||
| 16 | 0.065 | 0.245 | 0.2152 | ||
| Stainless steel tubing dimensions | 7/16 | 18 | 0.049 | 0.340 | 0.2036 |
| Stainless steel tubing dimensions | 1/2 | 20 | 0.035 | 0.430 | 0.1738 |
| 18 | 0.049 | 0.402 | 0.2360 | ||
| 16 | 0.065 | 0.370 | 0.3020 | ||
| Stainless steel tubing dimensions | 5/8 | 20 | 0.035 | 0.555 | 0.2205 |
| 18 | 0.049 | 0.527 | 0.3014 | ||
| 16 | 0.065 | 0.495 | 0.3888 | ||
| Stainless steel tubing dimensions | 3/4 | 18 | 0.049 | 0.652 | 0.3668 |
| 16 | 0.065 | 0.620 | 0.4755 | ||
| 14 | 0.083 | 0.584 | 0.5913 | ||
| Stainless steel tubing dimensions | 7/8 | 18 | 0.049 | 0.777 | 0.4323 |
| 16 | 0.065 | 0.745 | 0.5623 | ||
| 11 | 0.120 | 0.635 | 0.9676 | ||
| Stainless steel tubing dimensions | 1 | 20 | 0.035 | 0.930 | 0.3607 |
| 18 | 0.049 | 0.902 | 0.4977 | ||
| 16 | 0.065 | 0.870 | 0.6491 | ||
| 14 | 0.083 | 0.834 | 0.8129 | ||
| 11 | 0.120 | 0.760 | 1.1278 | ||
| Stainless steel tubing dimensions | 1-1/4 | 11 | 0.120 | 1.010 | 1.4480 |
How Is Stainless Steel Tubing Measured?
Because stainless steel tube is used in structural applications, the dimensions and tolerances must be precise.
The tube’s outside diameter (OD) and wall thickness (WT) almost often determine sizes.
The measured and declared ODs are within very near if not exact, tolerances. As a result, a one-inch tube will have a one-inch OD and a WT that meets the requirements.
The tube’s ID (Inside Diameter) decreases as the wall thickness decreases; however, this does not affect the tube’s measurement. (Read Pop Rivets Sizes Chart)
Stainless Steel Tubing Differences
Different tubing has different measurement protocols.
Hypodermic
Stainless steel hypodermic tubes are used in various medical and industrial applications.
As the name implies, such tubing is noted for its simplicity of cleaning and use. Most hypodermic needles are made of grade 304 stainless steel tubing, which has a thin wall and can be beveled and deburred for a high-quality finish.
Hypodermic stainless steel tubing can be used for blunt needles for pumping tires, rafts, balls, and other inflatable equipment.
Hypodermic tubing differs as it isn’t measured the same way as regular stainless steel tubing. Instead, the gauge of materials on the outside diameter and internal diameter determines the size, spanning from 3 gauge to 33 gauge.
Fractional/Metric/Square Steel Tubing
The OD and wall thickness of stainless steel tubing are measured in fractional, metric, and square units. For structural purposes that require exceptional strength and corrosion resistance, fractional tubing is often made of 304 stainless steel or 316 stainless steel.
Metric stainless steel tubing with sizes ranging from 1 mm OD/.254 mm Wall (.040″ OD/.010) to 26 mm OD / 1.32 mm wall (1.024″ OD.052″) is used for high-pressure hydraulic and pneumatic applications.
For its enhanced mechanical qualities, stainless steel square tubing is used in various home and commercial applications.
It’s prized for its durability, high corrosion resistance, and aesthetic appeal, as well as its ability to tolerate harsh weather conditions.
Is Stainless Tubing Measured By ID or OD?
| Stainless Steel Tubing Dimensions | |||||
|---|---|---|---|---|---|
| OD inches | Average Wall Size in inches | D/t Ratio | ID inches | Tubing Cross Sectional Area (in2) | Internal Area (in2) |
| 0.250 | 0.020 | 12.50 | 0.210 | 0.0145 | 0.0346 |
| 0.250 | 0.028 | 8.93 | 0.194 | 0.0195 | 0.0296 |
| 0.250 | 0.035 | 7.14 | 0.180 | 0.0236 | 0.0254 |
| 0.250 | 0.049 | 5.10 | 0.152 | 0.0309 | 0.0181 |
| 0.250 | 0.065 | 3.85 | 0.120 | 0.0378 | 0.0113 |
| 0.375 | 0.020 | 18.75 | 0.335 | 0.0223 | 0.0881 |
| 0.375 | 0.028 | 13.39 | 0.319 | 0.0305 | 0.0799 |
| 0.375 | 0.035 | 10.71 | 0.305 | 0.0374 | 0.0731 |
| 0.375 | 0.049 | 7.65 | 0.277 | 0.0502 | 0.0603 |
| 0.375 | 0.065 | 5.77 | 0.245 | 0.0633 | 0.0471 |
| 0.500 | 0.020 | 25.00 | 0.460 | 0.0302 | 0.1662 |
| 0.500 | 0.028 | 17.86 | 0.444 | 0.0415 | 0.1548 |
| 0.500 | 0.035 | 14.29 | 0.430 | 0.0511 | 0.1452 |
| 0.500 | 0.049 | 10.20 | 0.402 | 0.0694 | 0.1213 |
| 0.500 | 0.065 | 7.69 | 0.370 | 0.0888 | 0.1075 |
| 0.500 | 0.083 | 6.02 | 0.334 | 0.1087 | 0.0876 |
| 0.625 | 0.020 | 31.25 | 0.585 | 0.0380 | 0.2688 |
| 0.625 | 0.028 | 22.32 | 0.569 | 0.0525 | 0.2543 |
| 0.625 | 0.035 | 17.86 | 0.555 | 0.0649 | 0.2419 |
| 0.625 | 0.049 | 12.76 | 0.527 | 0.0887 | 0.2181 |
| 0.625 | 0.065 | 9.62 | 0.495 | 0.1144 | 0.1924 |
| 0.625 | 0.083 | 7.53 | 0.459 | 0.1413 | 0.1655 |
| 0.625 | 0.095 | 6.58 | 0.435 | 0.1582 | 0.1486 |
| 0.625 | 0.109 | 5.73 | 0.407 | 0.1767 | 0.1301 |
| 0.750 | 0.028 | 26.79 | 0.694 | 0.0635 | 0.3783 |
| 0.750 | 0.035 | 21.43 | 0.680 | 0.0786 | 0.3632 |
| 0.750 | 0.049 | 15.31 | 0.652 | 0.1079 | 0.3339 |
| 0.750 | 0.065 | 11.54 | 0.620 | 0.1399 | 0.3019 |
| 0.750 | 0.083 | 9.04 | 0.584 | 0.1739 | 0.2679 |
| 0.750 | 0.095 | 7.89 | 0.560 | 0.1955 | 0.2463 |
| 0.750 | 0.109 | 6.88 | 0.532 | 0.2195 | 0.2223 |
| 0.750 | 0.120 | 6.25 | 0.510 | 0.2375 | 0.2043 |
| 0.875 | 0.020 | 43.75 | 0.835 | 0.0537 | 0.5476 |
| 0.875 | 0.028 | 31.25 | 0.819 | 0.0745 | 0.5268 |
| 0.875 | 0.035 | 25.00 | 0.805 | 0.0924 | 0.5090 |
| 0.875 | 0.049 | 17.86 | 0.777 | 0.1272 | 0.4742 |
| 0.875 | 0.065 | 13.46 | 0.745 | 0.1654 | 0.4359 |
| 0.875 | 0.083 | 10.54 | 0.709 | 0.2065 | 0.3948 |
| 0.875 | 0.095 | 9.21 | 0.685 | 0.2328 | 0.3685 |
| 0.875 | 0.109 | 8.03 | 0.657 | 0.2623 | 0.3390 |
| 0.875 | 0.120 | 7.29 | 0.635 | 0.2846 | 0.3167 |
| 1.000 | 0.028 | 35.71 | 0.944 | 0.0855 | 0.6999 |
| 1.000 | 0.035 | 28.57 | 0.930 | 0.1061 | 0.6793 |
| 1.000 | 0.049 | 20.41 | 0.902 | 0.1464 | 0.6390 |
| 1.000 | 0.065 | 15.38 | 0.870 | 0.1909 | 0.5945 |
| 1.000 | 0.083 | 12.05 | 0.834 | 0.2391 | 0.5463 |
| 1.000 | 0.095 | 10.53 | 0.810 | 0.2701 | 0.5153 |
| 1.000 | 0.109 | 9.17 | 0.782 | 0.3051 | 0.4803 |
| 1.000 | 0.120 | 8.33 | 0.760 | 0.3318 | 0.4536 |
| 1.000 | 0.134 | 7.46 | 0.732 | 0.3646 | 0.4208 |
| 1.250 | 0.035 | 35.71 | 1.180 | 0.1336 | 1.0936 |
| 1.250 | 0.049 | 25.51 | 1.152 | 0.1849 | 1.0423 |
| 1.250 | 0.065 | 19.23 | 1.120 | 0.2420 | 0.9852 |
| 1.250 | 0.083 | 15.06 | 1.084 | 0.304L3 | 0.9229 |
| 1.250 | 0.095 | 13.16 | 1.060 | 0.3447 | 0.8825 |
| 1.250 | 0.109 | 11.47 | 1.032 | 0.3907 | 0.8365 |
| 1.250 | 0.120 | 10.42 | 1.010 | 0.4260 | 0.8012 |
| 1.250 | 0.134 | 9.33 | 0.982 | 0.4698 | 0.7574 |
| 1.500 | 0.035 | 42.86 | 1.430 | 0.1611 | 0.4763 |
| 1.500 | 0.049 | 30.61 | 1.402 | 0.2234 | 1.5438 |
| 1.500 | 0.065 | 23.08 | 1.370 | 0.2930 | 1.4741 |
| 1.500 | 0.083 | 18.07 | 1.334 | 0.3695 | 1.3977 |
| 1.500 | 0.095 | 15.79 | 1.310 | 0.4193 | 1.3478 |
| 1.500 | 0.109 | 13.76 | 1.282 | 0.4763 | 1.2908 |
| 1.500 | 0.120 | 12.50 | 1.260 | 0.5202 | 1.2469 |
| 1.500 | 0.134 | 11.19 | 1.232 | 0.5750 | 1.1921 |
| 1.500 | 0.148 | 10.14 | 1.204 | 0.6286 | 1.1385 |
| 1.750 | 0.035 | 50.00 | 1.680 | 0.1886 | 2.2167 |
| 1.750 | 0.049 | 40.82 | 1.902 | 0.3003 | 2.8413 |
| 1.750 | 0.065 | 26.92 | 1.620 | 0.3441 | 2.0612 |
| 1.750 | 0.083 | 21.08 | 1.584 | 0.4347 | 1.9706 |
| 1.750 | 0.095 | 18.42 | 1.560 | 0.4939 | 1.9113 |
| 1.750 | 0.109 | 16.06 | 1.532 | 0.5619 | 1.8433 |
| 1.750 | 0.120 | 14.58 | 1.510 | 0.6145 | 1.7908 |
| 1.750 | 0.134 | 13.06 | 1.482 | 0.6803 | 1.7250 |
| 1.750 | 0.148 | 11.82 | 1.454 | 0.7449 | 1.6604 |
| 1.750 | 0.165 | 10.61 | 1.420 | 0.8216 | 1.5837 |
| 2.000 | 0.035 | 57.14 | 1.930 | 0.2161 | 2.9255 |
| 2.000 | 0.049 | 40.82 | 1.902 | 0.3003 | 2.8413 |
| 2.000 | 0.065 | 30.77 | 1.870 | 0.3951 | 2.7465 |
| 2.000 | 0.083 | 24.10 | 1.834 | 0.4999 | 2.6417 |
| 2.000 | 0.095 | 21.05 | 1.810 | 0.5685 | 2.5730 |
| 2.000 | 0.109 | 18.35 | 1.782 | 0.6475 | 2.4941 |
| 2.000 | 0.120 | 16.67 | 1.760 | 0.7087 | 2.4328 |
| 2.000 | 0.134 | 14.93 | 1.732 | 0.7855 | 2.3561 |
| 2.000 | 0.148 | 13.51 | 1.704 | 0.8611 | 2.2805 |
| 2.000 | 0.165 | 13.51 | 1.670 | 0.9512 | 2.1904 |
What Are Standard Tubing Sizes?
It’s important to remember that stainless steel tubing and stainless steel piping are frequently mistaken.
However, the pipe carries gases and fluids rather than for structural purposes. Therefore, it has less rigorous sizing requirements than tubing, but they are generally nominal, i.e., approximate.
Stainless steel tube is used in nearly as many different ways as stainless steel alloys. Factories, mills, and manufacturing lines use stainless steel components in their machines and make stainless steel products.
Tubing comes in various shapes, sizes, and thicknesses, although it may conjure up pictures of a circle.
Stainless steel tubing comes in various shapes and sizes, including round, oval, rectangular, and square. Its many mechanical qualities make it an ideal material for a wide range of commercial, industrial, and manufacturing applications worldwide.
Boiler and superheater tubes and heat exchanger tubes are made of seamless ferritic and austenitic stainless-steel tubes. (Learn How To Clean Stainless Steel Jewelry)
Tubing is available in various sizes and thicknesses, ranging from 1/8 inch to 5 inches inside diameter and.015 to—500-inch exterior diameter.
- ASTM A249 As a boiler, superheater, heat exchanger, or condenser tube, ASTM A249 welded tubes composed of austenitic stainless steel are used. Seamless tube specifications for diameters and thicknesses range from 1/8-inch internal diameter to 5 inches outside diameter, with wall thicknesses ranging from.015 to.320 inches.
- ASTM A269 Stainless steel tubing according to ASTM A269 for use at low and high temperatures. The tubing is available in various sizes and thicknesses, including 1/4-inch internal diameter and bigger tube and—020-inch tubing.
- ASTM A270 Thin wall tubing for use in sanitary, dairy, and food industries, ASTM A270 seamless tube, and welded austenitic stainless steel sanitary tubing TP 304, 304L, 316, and 316L sanitary tubing where outer diameters of up to 4 inches are available.
- ASTM A312 TP 304, 304L, 316, and 316L austenitic stainless steel sanitary tubing, ASTM A312 seamless tube, and welded austenitic stainless steel sanitary tubing, excellent for dairy and food sector. Sizes up to 4 inches in outer diameter are available.
- ASTM A511 Seamless stainless steel tube under ASTM A511 is suited for mechanical applications or high-temperature conditions. Tubing material sizes up to 12-3/4 inches can be cold finished or hot finished.
- ASTM A554 welded stainless steel tubing is available in diameters up to 4 inches in outer diameter and is ideal for mechanical and structural purposes.
- ASTM A778 welded unannealed austenitic stainless steel tube for low and moderate temperatures is the best choice. TP 304L, 316L, 317L, 321, and 347 stainless steel tubing has an outer diameter of up to 4 inches.
Gauge refers to the thickness of a tubing’s wall. For example, the Outside Diameter (OD) of stainless steel tubing is defined in inches.
Gauge is a unit of measurement for the diameter of a wire or the cross-sectional area of tubing.
You can calculate the tubing gauge when you know the outside diameter, internal diameter, and wall thickness.
Birmingham Wire Gauge (BWG) and Stubs Wire Gauge standards are used in the United States. BWG is a unit of measurement that may be translated to mm.
| Product | Seamless Steel Pipe | ERW pipe | LSAW pipe | SSAW pipe | Casing and Tubing |
|---|---|---|---|---|---|
| O.D | 13.72-914.4mm | 21.3-660mm | 406-1626mm | 219-3500mm | Casing Size: 4-1/2' - 20' (114.3 mm - 508 mm) Tubing Size: OD: 2-3/8' - 4-1/2' (60.3 mm - 114.3 mm) |
| W.T | 1.25-50mm | 1-20mm | 6-60mm | 5-26mm | 0.205' - 0.635 mm; Length: R1 (4.88 m - 7.62 m), R2(7.62 m - 10.36 m), R3 (10.36 m - longer) |
| Unit Length | 5.8/6/11.8/12m..etc | 5.8/6/11.8/12m..etc | 5.8/6/11.8/12m..etc | 5.8/6/11.8/12m..etc | |
| Material | GR.B, X42, X46, X52, S355JOH, S355J2H, St 44.0, P265GH, P235GH, P265TR1 | GR.B, St 37, St 52, S235, X42, X46, X52, X56, X60, X65, X70 | GR.B, St 37, St 52, S235, S355JRH, X42, X46, X52, X56, X60 | GR.B, St 37, St 52, S235, X42, X46, X52, X56, X60, X65, X70 | H40, J55, K55, N80, C75, L80, C90, T95, Q125 |
| Use Case | Chilled Water Pipe, Drinking water, Waste Water Structural Tube, Boiler Pipe, Oil and Gas transportation Mechanical Structure. | Low pressure liquid delivery, for water, gas and oil. | Low pressure liquid delivery, for water, gas and oil. | Low pressure liquid delivery, for water, gas and oil. | Conveying gas, water, oil, natural gas |
