How to Measure Threaded Pipe Size
More
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.
More
Extreme-Pressure Stainless Steel Threaded Pipe Fittings
With the strength to handle extreme pressures, these fittings can be used to connect equipment in hydraulic fluid lines. 316 stainless steel fittings have excellent corrosion resistance. BSPP and metric male threads have either a gasket or a gasket and washer to prevent leaks. UN/UNF (SAE Straight) threads are also known as O-ring boss threads; the male threads have a gasket to prevent leaks.
UN/UNF (SAE Straight)
Male Threads with Gasket
- Specifications Met: See table
- For Use With: See table
316 Stainless Steel | ||||||
|---|---|---|---|---|---|---|
| Thread Size (A) | Dash Size (A) | Thread Size (B) | Max. Pressure | For Use With | Each | |
UN/UNF (SAE Straight) Female × Metric Male | ||||||
| 1 5/16"-12 | 16 | M33 × 2 mm | 3,000 psi @ 72° F | Hydraulic Fluid (Petroleum Base), Oil, Water | 000000000 | 0000000 |
- For Use With:
NPTF: Hydraulic Fluid, Oil, Steam, Water
BSPP and Metric: Hydraulic Fluid, Oil, Water - Specifications Met:
NPTF: ASTM A479
Metric: DIN 7631, ISO 9974
BSPP: ISO 1179, ISO 8434-6
316 Stainless Steel | ||||
|---|---|---|---|---|
| Thread Size | Drive Size | Max. Pressure | Each | |
Metric Male | ||||
| M33 × 2 mm | 17 mm | 5,800 psi @ 72° F | 00000000 | 000000 |
High-Pressure Plated Brass Threaded Pipe Fittings
The plating on these brass fittings creates a shiny finish and provides extra protection in corrosive environments. Fittings have the strength to handle high-pressure applications.
Nickel-plated brass fittings provide better corrosion resistance than unplated brass fittings.
Through-wall fittings are also known as bulkhead couplings and panel-mount couplings; they mount through a wall or panel to create an inlet or outlet.
- For Use With: Air, Natural Gas, Oil, Water
Nickel-Plated Brass | |||||
|---|---|---|---|---|---|
Pipe Size | Thread Size | For Max. Wall Thick. | Max. Pressure | Each | |
BSPP Female × Metric Male | |||||
| 3/4 | M33 × 1.5 mm | 0.886" | 1,230 psi @ 72° F | 00000000 | 000000 |
Compact Extreme-Pressure Steel Threaded Pipe Fittings
These fittings are strong enough to handle extreme pressures, yet small enough to fit into cramped spaces. They are zinc-plated steel, which have better corrosion resistance than plain steel fittings. BSPP and metric male threads have either a gasket, or a gasket and washer, to prevent leaks.
Male Threads with
Gasket and Washer
- For Use With: See table
- Specifications Met: See table
| Pipe Size (A) | Dash Size (A) | Thread Size (B) | Max. Pressure | Material | For Use With | Specifications Met | Each | |
NPT Female × Metric Male | ||||||||
|---|---|---|---|---|---|---|---|---|
| 1 | 16 | M33 × 2 mm | 2,500 psi @ 72° F | Zinc Plated Steel | Air, Hydraulic Fluid, Oil, Water | ASME B1.20.3, DIN 7631, ISO 6149, ISO 9974 | 00000000 | 000000 |
- Temperature Range: -20° to 230° F
| For Thread Size | Gasket Material | Thickness | Each | |
For Metric Male | ||||
|---|---|---|---|---|
| M33 | Buna-N Rubber | 2mm | 00000000 | 00000 |
Low-Pressure Aluminum Threaded Pipe Fittings
In addition to being lightweight, these aluminum fittings offer good corrosion resistance. Use them in low-pressure flow applications. To prevent cracking, do not tighten more than a 1/4-turn past hand tight.
DIN 3852 fittings meet DIN standards for mating surface outer diameter. They have a Buna-N rubber gasket that resists grease, hydraulic oil, and motor oil—plus mild chemicals and water. The gasket stays in a groove undercut in the mating face, which prevents it from dropping out and from extruding when fittings are tightened. Black anodized and powder-coated fittings have a decorative matte black finish.
The contact surface on fittings with a flange extends beyond the external hex drive.
Male Threads
with Gasket
- For Use With: Air, Oil, Water
- Specifications Met: DIN 3852
- Pipe Nipples and Pipe: Use aluminum
18-8 Stainless Steel Key-Locking Inserts
Made of stainless steel, these inserts have good corrosion resistance. Drive the keys into the surrounding material for a more secure hold than thread-locking inserts. Use them to repair or change threads in soft metals such as aluminum. Inserts may be mildly magnetic. They’re comparable to Keensert inserts. Installation requires a drill bit, a standard tap, an installation tool, and a hammer.
Choose inserts with a thick wall for greater strength than thin-wall inserts, or to fill a large hole.
Black-Phosphate Steel Key-Locking Inserts
A black-phosphate finish provides mild corrosion resistance. Drive the keys into the surrounding material for a more secure hold than thread-locking inserts. Use them to repair or change threads in soft metals such as aluminum. They’re comparable to Keensert inserts. Installation requires a drill bit, a standard tap, an installation tool, and a hammer.
Choose inserts with a thick wall for greater strength than thin-wall inserts, or to fill a large hole with stripped threads.
Inserts | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
For Tap | Each | Installation Tools | |||||||||||
| Thread Size | Thread Pitch, mm | Thread Spacing | Thread Size | Thread Pitch, mm | Installed Lg. | Drill Bit Size | For Max. Hole Dia. | No. of Locking Keys | 1-9 | 10-Up | Each | ||
Black-Phosphate Steel with Thick Wall | |||||||||||||
| M24 | 2 | Fine | M33 | 2 | 33mm | 31 mm | 31mm | 4 | 000000000 | 000000 | 000000 | 000000000 | 000000 |
| M24 | 3 | Coarse | M33 | 2 | 33mm | 31 mm | 31mm | 4 | 000000000 | 00000 | 00000 | 000000000 | 00000 |
Screw-Locking Key-Locking Inserts
Forming the strongest hold of any of our threaded inserts, these inserts have a distorted internal thread to lock screws into place and keys that drive into surrounding material to prevent slipping and rotating. This creates a mechanical lock, which is stronger than the chemical lock from adhesive on thread-locking inserts. Because they’re made of a solid piece of metal, these inserts are also stronger than helical inserts, which are made of coiled wire. They're often used in molds, tools and dies, and suspension systems in vehicles to create completely new threads, add strong threads in soft metal, or replace existing threads that are damaged or need to be resized.
A dry-film lubricant makes it easy to install them and screw fasteners in. To install, use a tap to create the threads in your material and an installation tool to drive the keys into the material. All are made to tight tolerances with strictly controlled materials. Many inch sizes also meet military or aerospace standards for dimensions and material.
These inserts resist corrosion in wet environments. Cadmium-plated steel inserts are stronger than 18-8 stainless steel inserts.
Inserts with thick walls are most commonly used; they’re stronger than thin-wall inserts and are used in larger holes.
Key-Locking Inserts with Installation Tool
Drive the keys into the surrounding material for a more secure hold than thread-locking inserts. These inserts are used to repair or convert threads in soft metals such as aluminum. They’re comparable to Keensert inserts.
Black-phosphate steel inserts are mildly corrosion resistant.
Choose inserts with a thick wall for greater strength than thin-wall inserts, or to fill a large hole.
For Tap | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Thread Size | Thread Pitch, mm | Thread Spacing | Thread Size | Thread Pitch, mm | Installed Lg. | Drill Bit Size | For Max. Hole Dia. | No. of Locking Keys | No. of Inserts Included | Each | |
Black-Phosphate Steel with Thick Wall | |||||||||||
| M24 | 3 | Coarse | M33 | 2 | 33mm | 31 mm | 31mm | 4 | 2 | 000000000 | 0000000 |