How to Identify and Measure Fittings
Pipe size is an industry designation, not the actual size. View information about how to measure threaded and unthreaded pipe and pipe fittings.
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Precision Extreme-Pressure Stainless Steel Threaded Pipe Fittings
Made to tighter tolerances than other stainless steel pipe fittings, these are also known as instrumentation fittings. The male threads are rolled for extra strength in extreme-pressure applications. Fittings are commonly used to connect equipment in gas and hydraulic fluid lines. They are 316 stainless steel for excellent corrosion resistance.
For technical drawings and 3-D models, click on a part number.
- For Use With: Hydraulic Fluid, Liquid Nitrogen, Natural Gas, Steam, Water
- Specifications Met: ASME B1.20.1, ASME B31.1, ASME B31.3
316 Stainless Steel | |||||
|---|---|---|---|---|---|
Pipe Size | Dash Size | Max. Pressure | Max. Steam Pressure | Each | |
NPT Female | |||||
| 1/16 | __ | 7,500 psi @ 72° F | 7,500 psi @ 300° F | 000000000 | 000000 |
| 1/8 | 02 | 6,400 psi @ 72° F | 6,400 psi @ 300° F | 00000000 | 00000 |
| 1/4 | 04 | 6,600 psi @ 72° F | 6,600 psi @ 300° F | 00000000 | 00000 |
| 3/8 | 06 | 5,300 psi @ 72° F | 5,300 psi @ 300° F | 00000000 | 00000 |
| 1/2 | 08 | 5,200 psi @ 72° F | 5,200 psi @ 300° F | 00000000 | 00000 |
| 3/4 | 12 | 4,600 psi @ 72° F | 4,600 psi @ 300° F | 000000000 | 00000 |
| 1 | 16 | 4,400 psi @ 72° F | 4,400 psi @ 300° F | 000000000 | 00000 |
- For Use With: Hydraulic Fluid, Liquid Nitrogen, Natural Gas, Steam, Water
- Specifications Met:
1/2 Pipe Size: ASME B1.20.1, ASME B31.1, ASME B31.3, ASTM A182, ASTM A276, ASTM A479
All other sizes: ASME B1.20.1, ASME B31.1, ASME B31.3
316 Stainless Steel | ||||||
|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Drive Size | Max. Pressure | Max. Steam Pressure | Each | |
NPT Male | ||||||
| 1/16 | __ | 5/32" | 10,000 psi @ 72° F | 10,000 psi @ 300° F | 000000000 | 000000 |
| 1/8 | 02 | 3/16" | 9,100 psi @ 72° F | 9,100 psi @ 300° F | 000000000 | 00000 |
| 1/4 | 04 | 1/4" | 7,500 psi @ 72° F | 7,500 psi @ 300° F | 000000000 | 00000 |
| 3/8 | 06 | 5/16" | 7,200 psi @ 72° F | 7,200 psi @ 300° F | 000000000 | 00000 |
| 1/2 | 08 | 3/8" | 7,700 psi @ 72° F | 7,700 psi @ 300° F | 000000000 | 00000 |
- For Use With: Hydraulic Fluid, Liquid Nitrogen, Natural Gas, Steam, Water
- Specifications Met:
NPT: ASME B1.20.1, ASME B31.1, ASME B31.3
BSPT: ISO 7-1
316 Stainless Steel | ||||||
|---|---|---|---|---|---|---|
| Pipe Size | Dash Size | Plug Construction | Max. Pressure | Max. Steam Pressure | Each | |
NPT Male | ||||||
| 1/16 | __ | Hollow | 10,000 psi @ 72° F | 10,000 psi @ 300° F | 000000000 | 00000 |
| 1/8 | 02 | Solid | 9,700 psi @ 72° F | 9,700 psi @ 300° F | 00000000 | 0000 |
| 1/4 | 04 | Solid | 8,000 psi @ 72° F | 8,000 psi @ 300° F | 00000000 | 00000 |
| 3/8 | 06 | Solid | 7,600 psi @ 72° F | 7,600 psi @ 300° F | 00000000 | 00000 |
| 1/2 | 08 | Solid | 7,000 psi @ 72° F | 7,000 psi @ 300° F | 000000000 | 00000 |
| 3/4 | 12 | Solid | 7,300 psi @ 72° F | 7,300 psi @ 300° F | 000000000 | 00000 |
| 1 | 16 | Solid | 5,300 psi @ 72° F | 5,300 psi @ 300° F | 000000000 | 00000 |
BSPT Male | ||||||
| 1/8 | 02 | Solid | 6,100 psi @ 72° F | 6,100 psi @ 300° F | 000000000 | 00000 |
| 1/4 | 04 | Solid | 6,200 psi @ 72° F | 6,200 psi @ 300° F | 000000000 | 00000 |
| 3/8 | 06 | Solid | 5,000 psi @ 72° F | 5,000 psi @ 300° F | 000000000 | 00000 |
| 1/2 | 08 | Solid | 3,600 psi @ 72° F | 3,600 psi @ 300° F | 000000000 | 00000 |
| 3/4 | 12 | Solid | 4,300 psi @ 72° F | 4,300 psi @ 300° F | 000000000 | 00000 |
| 1 | 16 | Solid | 4,100 psi @ 72° F | 4,100 psi @ 300° F | 000000000 | 00000 |
Precision Extreme-Pressure Brass Threaded Pipe Fittings
Also known as instrumentation fittings, these have the most precise threads and the tightest tolerances of all the brass pipe fittings we offer. Fittings are brass for good corrosion resistance.
For technical drawings and 3-D models, click on a part number.
- For Use With: Air, Argon, Natural Gas, Nitrogen Gas, Oil, Oxygen, Steam, Water
- Specifications Met: ASME B1.20.1, ASME B31.1, ASME B31.3
- For Use With: Air, Argon, Natural Gas, Nitrogen Gas, Oil, Oxygen, Steam, Water
- Specifications Met: ASME B1.20.1, ASME B31.1, ASME B31.3
- For Use With: Air, Argon, Natural Gas, Nitrogen Gas, Oil, Oxygen, Steam, Water
- Specifications Met:
NPT: ASME B1.20.1, ASME B31.1, ASME B31.3
BSPT: ASME B31.3, DIN 2999, ISO 7.1
| Pipe Size | Plug Construction | Max. Pressure | Max. Steam Pressure | Each | |
NPT Male | |||||
|---|---|---|---|---|---|
| 1/8 | Hollow | 5,600 psi @ 72° F | 1,500 psi @ 300° F | 0000000 | 00000 |
| 1/4 | Hollow | 4,100 psi @ 72° F | 1,500 psi @ 300° F | 0000000 | 0000 |
| 3/8 | Hollow | 4,000 psi @ 72° F | 1,500 psi @ 300° F | 0000000 | 00000 |
| 1/2 | Hollow | 3,900 psi @ 72° F | 1,500 psi @ 300° F | 0000000 | 00000 |
| 3/4 | Hollow | 3,800 psi @ 72° F | 1,500 psi @ 300° F | 0000000 | 00000 |
BSPT Male | |||||
| 1/4 | Hollow | 3,300 psi @ 72° F | 1,500 psi @ 300° F | 00000000 | 00000 |
| 1 | Hollow | 2,200 psi @ 72° F | 1,500 psi @ 300° F | 00000000 | 00000 |
Brass and Bronze Unthreaded Pipe Flanges
Bolt these flanges to equipment or to another same-size, flat-surface flange with a gasket (sold separately). They have good corrosion resistance.
Cap flanges are also known as blind flanges.
For technical drawings and 3-D models, click on a part number.
- For Use With: Air, Argon, Natural Gas, Nitrogen Gas, Oil, Oxygen, Water
- Pressure Class : 150
- Specifications Met: ASME B16.24
- Pipe Nipples and Pipe: Use Schedule 40 brass
Aluminum Quick-Connect Pipe Fittings for Compressed Air
Twist these fittings onto aluminum pipe for quick, sealed connections—no threading, soldering, or welding necessary. Use them to build a compressed air system in half the time it would take to build a copper or steel system. Also known as Unipipe fittings, they’re part of a quick-connect system that’s compatible with pipe from Unipipe, Transair, and Infinity.
Finger tighten the collar on the end of these fittings, then use a wrench for the final quarter turn. The inside of these fittings has a compression ring and O-ring to seal against the pipe. They’re easy to take apart as needed to modify your setup.
For technical drawings and 3-D models, click on a part number.
- For Use With: Air, Coolant, Nitrogen, Oil
- Temperature Range: 0° to 210° F
- Specifications Met: ASME B31.1, ASME B31.3, ASME B31.9
- Pipe Nipples and Pipe: Use Quick-Disconnect Aluminum
Plugs block the end of a fitting. They include a ¼ BSPP valve that can be used to exhaust your line or attach a pressure gauge. To install, remove the fitting's nut, collar, and grip ring. Insert the plug into the fitting, slide the collar on, and tighten the nut. Discard the connector's grip ring.
Ultra-High-Polish Gasket Fittings for Stainless Steel Tubing
- For Use With: Ammonia, Argon, Butane, Carbon Dioxide, Chloride, Fluoride, Fluorocarbon, Germane, Halide, Helium, Hydrogen, Krypton, Laser Gas, Natural Gas, Neon, Nitrogen, Oxygen, Silane, Sulfur Hexafluoride, Tungsten Hexafluoride, Xenon
- Temperature Range: -420° to 1000° F
- Tubing: Use with 316/316L stainless steel
- Compatible With: Swagelok® VCR
Polished to at least a 15 Ra finish on the inside, these fittings have an ultra-smooth interior surface that helps prevent contamination. Also known as ultra-high-purity fittings, they’re packed in a Class 100 clean room, cleaned, and double bagged. They are commonly used in semiconductor applications. Fittings use a metal gasket (sold separately), which generates fewer particles than a rubber gasket and creates a strong seal in high-pressure and high-vacuum applications. Fittings are 316 stainless steel for excellent corrosion resistance.
To assemble, place a gasket between the gasket ends before gently rotating the female-threaded fitting onto the male-threaded fitting. Tighten until 1/8 of a turn past finger tight.
For technical drawings and 3-D models, click on a part number.
Caps replace a female nut to close off the end of a line.
| For Tube OD | Material | Max. Pressure | Max. Vacuum | Environmental Rating | Each | |
| 1/8" | 316L Stainless Steel | 8,500 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 000000 |
| 1/4" | 316L Stainless Steel | 5,100 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 0000000 | 00000 |
| 1/2" | 316L Stainless Steel | 3,500 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 0000000 | 00000 |
| 3/4" | 316L Stainless Steel | 3,350 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 00000 |
| 1" | 316L Stainless Steel | 2,400 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 00000 |
Plugs replace a male nut to close off the end of a line.
| For Tube OD | Material | Max. Pressure | Max. Vacuum | Environmental Rating | Each | |
| 1/8" | 316L Stainless Steel | 8,500 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 00000 |
| 1/4" | 316L Stainless Steel | 5,100 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 0000000 | 00000 |
| 1/2" | 316L Stainless Steel | 3,500 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 0000000 | 00000 |
| 3/4" | 316L Stainless Steel | 3,350 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 00000 |
| 1" | 316L Stainless Steel | 2,400 psi @ 72° F | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 00000 |
| For Tube OD | Nut Material | Max. Pressure | Max. Vacuum | Lg. | Each | |
Male | ||||||
|---|---|---|---|---|---|---|
| 1/8" | 316L Stainless Steel | 8,500 psi @ 72° F | 10 -11 torr @ 72° F | 1/2" | 00000000 | 00000 |
| 1/4" | 316L Stainless Steel | 5,100 psi @ 72° F | 10 -11 torr @ 72° F | 17/32" | 00000000 | 0000 |
| 1/4" | 316L Stainless Steel | 5,100 psi @ 72° F | 10 -11 torr @ 72° F | 23/32" | 0000000 | 0000 |
| 1/2" | 316L Stainless Steel | 3,500 psi @ 72° F | 10 -11 torr @ 72° F | 13/16" | 0000000 | 00000 |
| 3/4" | 316L Stainless Steel | 3,350 psi @ 72° F | 10 -11 torr @ 72° F | 1" | 00000000 | 00000 |
| 1" | 316L Stainless Steel | 2,400 psi @ 72° F | 10 -11 torr @ 72° F | 1 3/16" | 00000000 | 00000 |
Female | ||||||
| 1/8" | 316L Stainless Steel | 8,500 psi @ 72° F | 10 -11 torr @ 72° F | 17/32" | 00000000 | 0000 |
| 1/4" | 316L Stainless Steel | 5,100 psi @ 72° F | 10 -11 torr @ 72° F | 13/16" | 0000000 | 0000 |
| 1/2" | 316L Stainless Steel | 3,500 psi @ 72° F | 10 -11 torr @ 72° F | 7/8" | 0000000 | 00000 |
| 3/4" | 316L Stainless Steel | 3,350 psi @ 72° F | 10 -11 torr @ 72° F | 1 1/8" | 00000000 | 00000 |
| 1" | 316L Stainless Steel | 2,400 psi @ 72° F | 10 -11 torr @ 72° F | 1 11/32" | 00000000 | 00000 |
Retaining
Tabs
Nickel gaskets are softer than stainless steel gaskets, so they won’t wear down sealing surfaces as much, and they’re easier to tighten. They’re reactive to carbon monoxide and ozone, so they shouldn’t be used with those chemicals.
Hard and heat resistant, stainless steel gaskets can be used in a wider range of applications than nickel gaskets such as carbon monoxide and ozone. However, they’re harder to tighten than nickel gaskets, and they’ll wear down sealing surfaces more quickly.
Silver-plated stainless steel gaskets are softer than unfinished stainless steel gaskets, so they won’t wear down sealing surfaces as much, and they’re easier to tighten. However, they oxidize when exposed to air, and silver particles might flake off during assembly.
Gaskets with retaining tabs stay in place during installation, so you don’t have to hold the gasket while fastening fittings together. This also means they’re less likely to scratch or nick your fittings by rotating during installation.
| For Tube OD | Max. Vacuum | Environmental Rating | Each | |
Nickel Gasket | ||||
|---|---|---|---|---|
| 1/4" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 00000 |
| 1/2" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 0000 |
316L Stainless Steel Gasket | ||||
| 1/4" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 0000000 | 0000 |
| 1/2" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 0000000 | 0000 |
| 3/4" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 00000 |
| 1" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 00000 |
Silver-Plated 316L Stainless Steel Gasket | ||||
| 1/4" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 0000 |
| 1/2" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 0000 |
316L Stainless Steel Gasket with Retaining Tabs | ||||
| 1/4" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 0000 |
| 1/2" | 10 -11 torr @ 72° F | Fed. Std. Class 100 | 00000000 | 0000 |
Push-to-Connect Fittings for Plastic Tubing—High-Purity
- For Use With: Air, Nitrogen, Water
- Temperature Range: 32° to 100° F
- Tubing: Use with polypropylene plastic
Also known as instant fittings, these connect to tubing with a push, and an internal gripping ring and O-ring hold the tubing tight. To disconnect, push on the release ring and pull the tubing out of the fitting. Fittings are produced in a clean room and are double bagged to prevent dirt and moisture from contaminating the inside. They are polypropylene, which has excellent impact and abrasion resistance.
For technical drawings and 3-D models, click on a part number.
Plugs insert into the push-to-connect end of another fitting.
| Tube Stem OD | Material | Color | Max. Pressure | Each | |
| 1/4" | Polypropylene Plastic | White | 100 psi @ 72° F | 00000000 | 00000 |
| 3/8" | Polypropylene Plastic | White | 100 psi @ 72° F | 00000000 | 0000 |
| 1/2" | Polypropylene Plastic | White | 100 psi @ 72° F | 00000000 | 0000 |
| 4mm | Polypropylene Plastic | White | 140 psi @ 72° F | 00000000 | 0000 |
| 6mm | Polypropylene Plastic | White | 140 psi @ 72° F | 00000000 | 0000 |
| 8mm | Polypropylene Plastic | White | 140 psi @ 72° F | 00000000 | 0000 |
| 12mm | Polypropylene Plastic | White | 140 psi @ 72° F | 00000000 | 0000 |
Quick-Install Pressure Test Fittings
Thread these fittings onto your testing equipment by hand for a secure connection in testing applications—no tools, tape, or sealant required. Use them with gauges and other equipment as a temporary connection. When pressure is applied, the O-ring on the outlet presses against the testing equipment, creating a tight seal.
For technical drawings and 3-D models, click on a part number.
| Pipe Size | Max. Pressure, psi | Temperature Range, °F | Gasket Material | For Use With | Each | |
NPT Male Inlet Plug | ||||||
|---|---|---|---|---|---|---|
416 Stainless Steel | ||||||
| 1/8 | 5,000 | -65° to 212° | Polyurethane Rubber | Air, Argon, Diesel Fuel, Fuel Oil, Gasoline, Hydraulic Fluid, Hydraulic Fluid (Petroleum Based), Natural Gas, Nitrogen, Oxygen, Water | 0000000 | 0000000 |
| 1/4 | 5,000 | -65° to 212° | Polyurethane Rubber | Air, Argon, Diesel Fuel, Fuel Oil, Gasoline, Hydraulic Fluid, Hydraulic Fluid (Petroleum Based), Natural Gas, Nitrogen, Oxygen, Water | 0000000 | 000000 |
| 3/8 | 4,000 | -65° to 212° | Polyurethane Rubber | Air, Argon, Diesel Fuel, Fuel Oil, Gasoline, Hydraulic Fluid, Hydraulic Fluid (Petroleum Based), Natural Gas, Nitrogen, Oxygen, Water | 0000000 | 000000 |
| 1/2 | 4,000 | -65° to 212° | Polyurethane Rubber | Air, Argon, Diesel Fuel, Fuel Oil, Gasoline, Hydraulic Fluid, Hydraulic Fluid (Petroleum Based), Natural Gas, Nitrogen, Oxygen, Water | 0000000 | 000000 |
| 3/4 | 4,000 | -65° to 212° | Polyurethane Rubber | Air, Argon, Diesel Fuel, Fuel Oil, Gasoline, Hydraulic Fluid, Hydraulic Fluid (Petroleum Based), Natural Gas, Nitrogen, Oxygen, Water | 0000000 | 000000 |
| 1 | 4,000 | -65° to 212° | Polyurethane Rubber | Air, Argon, Diesel Fuel, Fuel Oil, Gasoline, Hydraulic Fluid, Hydraulic Fluid (Petroleum Based), Natural Gas, Nitrogen, Oxygen, Water | 0000000 | 000000 |
Pressure Test Fittings
Check pressure without permanently installing a gauge. Fittings have an NPT male connection for installation in your pipe or tank. Wrench-tighten the fitting onto your equipment, then insert the gauge adapter (sold separately) into the fitting. Connect gauge adapters to gauges with 1/4 pipe size NPT male threads.
Plugs | Gauge Adapters | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | Thread Size | Thread Pitch, mm | Max. Pressure, psi | Gasket Material | Ht. | For Use With | Each | Each | ||
NPT Male × Metric Male | ||||||||||
Steel | ||||||||||
| 1/8 | M16 | 2 | 5,800 | Fluoroelastomer Rubber | 1 1/2" | Air, Argon, Diesel Fuel, Fuel Oil, Gasoline, Hydraulic Fluid, Hydraulic Fluid (Petroleum Based), Natural Gas, Nitrogen, Water | 0000000 | 000000 | 0000000 | 000000 |
| 1/4 | M16 | 2 | 5,800 | Fluoroelastomer Rubber | 1 1/2" | Air, Argon, Diesel Fuel, Fuel Oil, Gasoline, Hydraulic Fluid, Hydraulic Fluid (Petroleum Based), Natural Gas, Nitrogen, Water | 0000000 | 00000 | 0000000 | 00000 |