1/4"-28 Nipples | McMaster-Carr

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	System of Measurement System of Measurement

Inch

Metric

	Thread Size Thread Size	Show

1/4"-28

	Thread Size Thread Size	Hide

	Thread Type Thread Type

UN/UNF (SAE Straight)

UNF

	Pipe Size Pipe Size

1/16

1/8

1/4

	Shape Shape


Straight	90° Elbow

45° Elbow	65° Elbow

	Material Material

	Gender Gender

Male

Female

	For Use With For Use With

	Grease Fitting Style Grease Fitting Style


Standard	Flush

	Type Type

	Adapter

	Overall Height Overall Height

	Thread Length Thread Length

	Finish Finish

Zinc Plated

Anodized

	Shank Length Shank Length

	Hex Size Hex Size

	Check Valve Type Check Valve Type

Ball

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant

RoHS Compliant with
Exemptions

	Maximum Pressure Maximum Pressure

	Connection Style Connection Style

Threaded

Barbed

Quick Turn

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

	Specifications Met Specifications Met

ASME

ASTM

FDA Compliant

	Shank Type Shank Type

Threaded

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64 Products

About Grease Fitting Threads

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.

Miniature Medium-Pressure Stainless Steel Threaded Pipe Fittings

When space is at a premium choose these compact fittings. Though small in size, they have the strength to handle medium-pressure applications. Fittings are stainless steel for very good corrosion resistance.

Metric, BSPP, and UN/UNF (SAE Straight) male threads have a gasket to protect against leaks. Made from fluoroelastomer, these gaskets resist chemicals, including benzene, butyl alcohol, and ethylene glycol. UN/UNF (SAE Straight) threads are also known as O-ring boss threads.

For technical drawings and 3-D models, click on a part number.

Straight Adapters, Male

BSPP, Metric, and
UN/UNF (SAE Straight)
Male Threads with Gasket

For Use With: Air, Natural Gas, Oil, Steam, Water
Specifications Met: ASTM A314, ASTM A320, ASTM A582

					303 Stainless Steel
Pipe Size	Thread Size	Max. Pressure	Max. Steam Pressure	Gasket Material		Each
NPT Male × UN/UNF (SAE Straight) Male
1/16	1/4"-28	500 psi @ 72° F	100 psi @ 350° F	Fluoroelastomer Rubber	00000000	000000
1/8	1/4"-28	500 psi @ 72° F	100 psi @ 350° F	Fluoroelastomer Rubber	000000	00000
1/4	1/4"-28	500 psi @ 72° F	100 psi @ 350° F	Fluoroelastomer Rubber	00000000	00000

Miniature Medium-Pressure Aluminum Threaded Pipe Fittings

Their small size makes these miniature fittings a good choice for cramped, confined spaces. They are designed to handle medium-pressure applications. Fittings are aluminum, which is lightweight with good corrosion resistance.

Metric and UN/UNF (SAE Straight) male threads have a gasket to protect against leaks. UN/UNF (SAE Straight) threads are also known as O-ring boss threads.

For technical drawings and 3-D models, click on a part number.

Straight Adapters, Male

Metric and UN/UNF
(SAE Straight) Male
Threads with Gasket

For Use With: Air, Oil, Water
Specifications Met: ASME B1.20.1, ASTM B241

NPT Male × UN/UNF (SAE Straight) Male
Pipe Size	Thread Size	Max. Pressure		Each
1/16	1/4"-28	150 psi @ 72° F	00000000	00000
1/8	1/4"-28	150 psi @ 72° F	00000000	0000
1/4	1/4"-28	150 psi @ 72° F	00000000	00000

Choose-a-Color Aluminum Low-Pressure Barbed Tube Fittings for Air and Water

For Use With: Air, Lubricated Air, Water
Temperature Range: -40° to 230° F
Tubing: Use with hard (Durometer 75A-60D) EVA plastic, polyethylene plastic, polyurethane rubber or PVDF plastic

Color-code fittings for easy identification. Fittings are aluminum, which is lightweight with good corrosion resistance. The barb grips onto tubing, providing a secure hold with no clamp required.

Metric and UN/UNF (SAE Straight) male threads have a gasket for a tight seal. UN/UNF (SAE Straight) threads are also known as O-ring boss threads.

For technical drawings and 3-D models, click on a part number.

Straight Adapters, Tube × Male Threaded Pipe

Metric and UN/UNF
(SAE Straight) Male
Threads with Gasket

UN/UNF (SAE Straight) Threads
For Tube ID	Thread Size	Material	Gasket Material	Max. Pressure	Choose a Color		Each
1/16"	1/4"-28	Anodized Aluminum	Fiber	125 psi @ 72° F	Black, Blue, Red	00000000	00000
1/8"	1/4"-28	Anodized Aluminum	Fiber	125 psi @ 72° F	Black, Blue, Red	00000000	0000
0.17"	1/4"-28	Anodized Aluminum	Fiber	125 psi @ 72° F	Black, Blue, Red	00000000	0000
1/4"	1/4"-28	Anodized Aluminum	Fiber	125 psi @ 72° F	Black, Blue, Red	00000000	0000

Straight Adapters, Tube × Female Threaded Pipe

UN/UNF (SAE Straight) Threads
For Tube ID	Thread Size	Material	Max. Pressure	Choose a Color		Each
1/16"	1/4"-28	Anodized Aluminum	125 psi @ 72° F	Black, Blue, Red	00000000	000000

Aluminum Low-Pressure Barbed Tube Fittings for Air and Water

For Use With: Air, Lubricated Air, Water
Temperature Range: -40° to 230° F
Tubing: Use with hard (Durometer 75A-60D) EVA plastic, polyethylene plastic, polyurethane rubber or PVDF plastic

Made of aluminum, these fittings are lighter in weight than other metal barbed tube fittings and have good corrosion resistance. The barb grips onto tubing, providing a secure hold with no clamp required.

Metric, BSPP, and UN/UNF (SAE Straight) male threads have a gasket or O-ring for a tight seal. UN/UNF (SAE Straight) threads are also known as O-ring boss threads.

For technical drawings and 3-D models, click on a part number.

Straight Adapters, Tube × Male Threaded Pipe

Metric and UN/UNF
(SAE Straight) Male
Threads with Gasket

UN/UNF (SAE Straight) Threads
For Tube ID	Thread Size	Material	Gasket Material	Max. Pressure		Each
1/16"	1/4"-28	Aluminum	Fiber	125 psi @ 72° F	00000000	00000
1/8"	1/4"-28	Aluminum	Fiber	125 psi @ 72° F	00000000	0000
0.17"	1/4"-28	Aluminum	Fiber	125 psi @ 72° F	00000000	0000
1/4"	1/4"-28	Aluminum	Fiber	125 psi @ 72° F	00000000	0000

Tight-Seal Moisture-Resistant Plastic Barbed Tube Fittings for Air and Water

Temperature Range: -20° to 280° F
Tubing: Use with firm or soft (Durometer 50A-90A) polyurethane rubber or PVC plastic
Specifications Met: FDA Compliant 21 CFR 177.2470

Fittings have a single barb that creates a smooth clamping surface for extra-tight connections that minimize leaks. Made of acetal, they won’t absorb water and lose strength, even in high-humidity environments.

For technical drawings and 3-D models, click on a part number.

Straight Adapters, Tube × Male Threaded Pipe

UNF Threads
For Tube ID	Thread Size	Material	Color	Clarity	Max. Pressure		Each
1/16"	1/4"-28	Acetal Plastic	White	Semi-Clear	Not Rated	00000000	00000
3/32"	1/4"-28	Acetal Plastic	White	Semi-Clear	Not Rated	00000000	000
1/8"	1/4"-28	Acetal Plastic	White	Semi-Clear	Not Rated	00000000	0000
5/32"	1/4"-28	Acetal Plastic	White	Semi-Clear	Not Rated	00000000	000
3/16"	1/4"-28	Acetal Plastic	White	Semi-Clear	Not Rated	00000000	000

Plastic Quick-Turn Tube Couplings for Air and Water

For Use With: Polycarbonate Plastic: Air
Nylon Plastic: Air, Water
Polypropylene Plastic: Water
Temperature Range: Nylon Plastic, Polycarbonate Plastic: -20° to 200° F
Polypropylene Plastic: 35° to 150° F
Tubing: Use with soft (Durometer 40A-65A) PVC plastic or silicone rubber

Made of plastic, these couplings are lighter in weight than metal quick-turn couplings. Also known as luer lock couplings, they consist of a plug and socket (sold separately) that connect with a half turn. They have a compact body for easy installation in tight spaces. Plugs and sockets are open-flow style, so there is no shut-off valve to stop the flow when the coupling is separated. They have a universal connection, so the plugs will connect to any of the sockets, regardless of the pipe or tube size.

Nylon plugs and sockets have good impact and abrasion resistance. Polypropylene plugs and sockets are moisture resistant and won’t absorb water and lose strength, even in high-humidity environments.

Note: For a complete coupling, order a plug and a socket.

For technical drawings and 3-D models, click on a part number.

Straight Plugs, Male Threaded Pipe

UN/UNF (SAE Straight) Threads
Thread Size	Material	Color	Clarity	Max. Pressure	Pkg. Qty.		Pkg.
1/4"-28	Nylon Plastic	White	Opaque	40 psi @ 72° F	10	000000000	00000
1/4"-28	Polypropylene Plastic	White	Semi-Clear	40 psi @ 72° F	10	000000000	0000

Stainless Steel Quick-Turn Tube Couplings for Air

Made of stainless steel, these couplings stand up to wet environments. Also known as luer lock couplings, they consist of a plug and socket (sold separately) that connect with a half turn. They have a compact body, so they’re easy to fit in tight spaces. Plugs and sockets are open-flow style, so there is no shut-off valve to stop the flow when the coupling is separated. They have a universal connection, so the plugs will connect to any of the sockets, regardless of the pipe or tube size.

303 stainless steel couplings have very good corrosion resistance. 316 stainless steel couplings have excellent corrosion resistance.

Note: For a complete coupling, order a plug and a socket.

For technical drawings and 3-D models, click on a part number.

Plugs, Male Threaded Pipe

Temperature Range: 32° to 300° F

		303 Stainless Steel		316 Stainless Steel
Thread Size	Max. Pressure		Each		Each
UN/UNF (SAE Straight) Threads
1/4"-28	30 psi @ 72° F	0000000	000000	0000000	000000

Barbed Fittings for Plastic and Rubber Tubing—Chemicals

For Use With: Alcohol, Coolant, Mild Bases
Temperature Range: See table
Tubing: Use with firm (Durometer 75A-80A) polyurethane rubber, PVC plastic, or Viton® fluoroelastomer rubber

Minimize leaks in your line—these fittings have a single barb that creates a smooth clamping surface for extra-tight connections. Fittings are polypropylene, which has very good chemical resistance as well as impact and abrasion resistance.

For technical drawings and 3-D models, click on a part number.

Straight Adapters, Tube × Male Threaded Pipe

UN/UNF (SAE Straight) Threads
For Tube ID	Thread Size	Material	Color	Clarity	Max. Pressure	Temp. Range, ° F	Pkg. Qty.		Pkg.
1/4"	1/4"-28	Polypropylene Plastic	White	Semi-Clear	120 psi @ 72° F	32° to 250°	10	00000000	00000

Grease Fittings

These fittings are also known as hydraulic grease fittings.

Zinc-plated steel fittings have mild corrosion resistance. Brass fittings are more corrosion resistant than zinc-plated steel fittings. 303 stainless steel fittings are more corrosion resistant than brass fittings and have good chemical resistance. 400 nickel fittings are the most corrosion resistant and can be used in caustic environments, such as those involving salt water, sulfuric acid, and alkalies.

Fittings with a check valve prevent grease from leaking when pressure causes backward flow. The valve stays closed when not in use to keep out dirt and other contaminants.

UNF and UNEF threads are similar to threads on a machine screw or bolt. They require a sealant, such as an O-ring, to minimize leakage. SAE-LT threads are tapered but designed to be installed into a 1/4"-28 straight-thread UNF hole.

For technical drawings and 3-D models, click on a part number.

Straight with Male Threads

Straight with
Male
Threads

									Pkg.
Material	Overall Ht.	Shank Lg.	Thread Lg.	Hex Size	Max. Pressure, psi	Check Valve Type	Pkg. Qty.		1-9	10-Up
1/4"-28 UNF Threads
Zinc-Plated Steel	33/64"	5/32"	5/64"	9/32"	10,000	Ball	10	0000000	00000	00000
Brass	17/32"	5/32"	5/32"	9/32"	10,000	Ball	5	000000	0000	0000
Brass	19/32"	7/32"	7/32"	9/32"	10,000	Ball	5	000000	0000	0000
1/4"-28 SAE-LT Threads
Zinc-Plated Steel	17/32"	3/16"	1/8"	5/16"	10,000	Ball	10	0000000	0000	0000
Zinc-Plated Steel	11/16"	23/64"	13/64"	5/16"	10,000	Ball	10	0000000	0000	0000
Zinc-Plated Steel	31/32"	5/8"	13/64"	5/16"	10,000	Ball	10	0000000	0000	0000
Zinc-Plated Steel	1 1/8"	25/32"	13/64"	5/16"	10,000	Ball	10	0000000	00000	00000
Zinc-Plated Steel	1 5/8"	1"	13/64"	5/16"	10,000	Ball	5	0000000	00000	0000
303 Stainless Steel	17/32"	3/16"	7/64"	5/16"	10,000	Ball	5	0000000	00000	00000
303 Stainless Steel	19/32"	7/32"	7/32"	9/32"	10,000	Ball	3	0000000	0000	0000
400 Nickel	17/32"	3/16"	3/16"	5/16"	10,000	Ball	1	0000000	0000	0000

90° Elbow with Male Threads

									Pkg.
Material	Overall Ht.	Thread Lg.	Shank Lg.	Hex Size	Max. Pressure, psi	Check Valve Type	Pkg. Qty.		1-9	10-Up
1/4"-28 UNF Threads
Brass	45/64"	7/32"	7/32"	11/32"	10,000	Ball	3	000000	000000	00000
1/4"-28 SAE-LT Threads
Zinc-Plated Steel	3/4"	13/64"	13/64"	3/8"	10,000	Ball	10	0000000	0000	0000
Zinc-Plated Steel	51/64"	5/16"	5/16"	3/8"	8,000	Ball	10	0000000	00000	0000
303 Stainless Steel	3/4"	7/64"	13/64"	3/8"	10,000	Ball	1	0000000	0000	0000
400 Nickel	3/4"	13/64"	13/64"	3/8"	10,000	Ball	1	0000000	00000	00000

65° Elbow with Male Threads

									Pkg.
Material	Overall Ht.	Thread Lg.	Shank Lg.	Hex Size	Max. Pressure, psi	Check Valve Type	Pkg. Qty.		1-9	10-Up
1/4"-28 SAE-LT Threads
Zinc-Plated Steel	49/64"	13/64"	13/64"	3/8"	8,000	Ball	10	0000000	00000	00000
Zinc-Plated Steel	25/32"	19/64"	19/64"	3/8"	10,000	Ball	10	0000000	0000	0000

45° Elbow with Male Threads

									Pkg.
Material	Overall Ht.	Thread Lg.	Shank Lg.	Hex Size	Max. Pressure, psi	Check Valve Type	Pkg. Qty.		1-9	10-Up
1/4"-28 UNF Threads
Zinc-Plated Steel	39/64"	1/8"	1/8"	3/8"	10,000	Ball	10	0000000	000000	000000
Brass	59/64"	7/32"	7/32"	11/32"	10,000	Ball	1	000000	0000	0000
1/4"-28 SAE-LT Threads
Zinc-Plated Steel	13/16"	13/64"	13/64"	3/8"	10,000	Ball	10	0000000	0000	0000
Zinc-Plated Steel	63/64"	5/16"	5/16"	3/8"	8,000	Ball	10	0000000	00000	0000
303 Stainless Steel	13/16"	13/64"	13/64"	3/8"	10,000	Ball	3	0000000	00000	00000

Flush-Style Grease Fittings

Use these fittings in tight spaces where protruding fittings won't work. They’re zinc-plated steel for mild corrosion resistance. An integral check valve prevents grease from leaking when pressure causes backward flow. The valve stays closed when not in use to keep out dirt and other contaminants.

Install Style C with a hex wrench.

UNF threads are similar to threads on a machine screw or bolt. They require a sealant, such as an O-ring, to minimize leakage.

For technical drawings and 3-D models, click on a part number.

										Pkg.
Style	Material	Overall Ht.	Shank Lg.	Thread Lg.	Hex Size	Max. Pressure, psi	Check Valve Type	Pkg. Qty.		1-9	10-Up
Straight with Male Threads
1/4"-28 UNF Threads
C	Zinc-Plated Steel	13/32"	19/64"	3/16"	5/16"	10,000	Ball	5	00000000	00000	00000

Self-Tapping Grease Fittings for Unthreaded Holes

Ensure a secure fit in unthreaded holes—these fittings cut threads as they’re installed. Install with a hex wrench. Fittings can be driven in, but then are not pressure rated. They're zinc-plated steel for mild corrosion resistance. All have an integral check valve that prevents grease from leaking when pressure causes backward flow. The valve stays closed when not in use to keep out dirt and other contaminants. These fittings are also known as hydraulic grease fittings.

SAE-LT threads are tapered.

For technical drawings and 3-D models, click on a part number.

Straight with Male Threads

										Pkg.
For Hole Dia.	Material	Overall Ht.	Shank Lg.	Thread Lg.	Hex Size	Max. Pressure, psi	Check Valve Type	Pkg. Qty.		1-9	10-Up
1/4"-28 SAE-LT Threads
0.23-0.235"	Zinc-Plated Steel	1/2"	5/64"	5/64"	9/32"	10,000	Ball	10	0000000	00000	00000
0.23-0.235"	Zinc-Plated Steel	37/64"	13/64"	13/64"	5/16"	10,000	Ball	10	0000000	0000	0000

90° Elbow with Male Threads

										Pkg.
For Hole Dia.	Material	Overall Ht.	Shank Lg.	Thread Lg.	Hex Size	Max. Pressure, psi	Check Valve Type	Pkg. Qty.		1-9	10-Up
1/4"-28 SAE-LT Threads
0.23-0.235"	Zinc-Plated Steel	3/4"	13/64"	13/64"	3/8"	10,000	Ball	10	0000000	00000	00000

45° Elbow with Male Threads

										Pkg.
For Hole Dia.	Material	Overall Ht.	Shank Lg.	Thread Lg.	Hex Size	Max. Pressure, psi	Check Valve Type	Pkg. Qty.		1-9	10-Up
1/4"-28 SAE-LT Threads
0.23-0.235"	Zinc-Plated Steel	13/16"	13/64"	13/64"	3/8"	10,000	Ball	10	0000000	00000	00000

Grease Fitting Adapters

When the size or thread type of a fitting doesn't match an existing opening, use these adapters to make the connection.

Zinc-plated steel adapters have mild corrosion resistance. 303 stainless steel adapters are more corrosion resistant than brass adapters and have good chemical resistance.

PTF and NPTF (Dryseal) threads are compatible with NPT threads. UNF threads are similar to threads on a machine screw or bolt. They require a sealant, such as an O-ring, to minimize leakage. SAE-LT threads are tapered but designed to be installed into a 1/4"-28 straight-thread UNF hole.

For technical drawings and 3-D models, click on a part number.

Straight

Connection
Male	Female	Material		Each
UNF 1/4"-28	NPT 1/8	Steel	0000000	00000
SAE-LT 1/4"-28	NPTF 1/8	Zinc-Plated Steel	0000000	0000
SAE-LT 1/4"-28	NPTF 1/8	303 Stainless Steel	0000000	00000
Metric M6 × 1 mm	UNF 1/4"-28	Zinc-Plated Steel	0000000	0000
Metric M8 × 1 mm	UNF 1/4"-28	Zinc-Plated Steel	0000000	00000
Metric M10 × 1 mm	UNF 1/4"-28	Zinc-Plated Steel	0000000	00000

90° Elbow

Connection
Male	Female	Material		Each
SAE-LT 1/4"-28	NPTF 1/8	Zinc-Plated Steel	0000000	000000
SAE-LT 1/4"-28	NPTF 1/8	303 Stainless Steel	0000000	00000

45° Elbow

Connection
Male	Female	Material		Each
UNF 1/4"-28	NPT 1/8	Steel	0000000	000000
SAE-LT 1/4"-28	NPTF 1/8	Zinc-Plated Steel	0000000	0000
SAE-LT 1/4"-28	NPTF 1/8	303 Stainless Steel	0000000	00000