1/4"-28 Couplings | 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

NPT

SAE-LT

UN/UNF (SAE Straight)

UNF

	Material Material

	Nut Type Nut Type


Coupling	Hex

	Length Length

	Width Width

3/8"

1/2"

	Type Type


Connector	Adapter

Reducing Adapter	Bushing

	Shape Shape


Straight	Hex

90° Elbow	65° Elbow

	Gender Gender

Female

Male

	Threading Threading

	Fully Threaded
	Partially Threaded

	Connection Style Connection Style

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

RoHS Compliant

RoHS Compliant with
Exemptions

	Quick-Turn Component Quick-Turn Component


Socket	Plug

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

DFARS Specialty Metals
COTS-Exempt

DFARS Specialty Metals
Compliant

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

REACH Compliant

	Thread Direction Thread Direction

	Right Hand

	Thread Fit Thread Fit

	Hex Length Hex Length

	Connection Type Connection Type


Pipe	Tube

	Drive Style Drive Style

	External Hex

	Thread Spacing Thread Spacing

Fine

	Finish Finish

313 Products

Pipe and Pipe Fittings

Miniature Medium-Pressure Stainless
Steel Threaded Pipe Fittings

When space is at a premium choose these compact fittings.

Miniature Medium-Pressure
Aluminum Threaded Pipe Fittings

Their small size makes these miniature fittings a good choice for cramped, confined spaces.

Standard-Wall Plastic Pipe Fittings for Water

Connect these fittings to Schedule 40 plastic pipe—they are the industry standard for residential and commercial low-pressure plumbing and water supply applications. They are plastic for good corrosion resistance.

Plastic Pipe Fittings for Oil

Made of corrosion-resistant plastic, these fittings won’t deteriorate when used in oil applications. They have high strength and impact resistance.

Tube Fittings for Plastic and Rubber Tubing—Air and Water

Brass Push-to-Connect Tube Fittings for Air

Made of brass, these fittings have good corrosion resistance.

Plastic Quick-Turn Tube Couplings for Air and Water

Made of plastic, these couplings are lighter in weight than metal quick-turn couplings.

Stainless Steel Quick-Turn Tube Couplings for Air

Made of stainless steel, these couplings stand up to wet environments.

Brass Quick-Turn Tube Couplings for Air

These brass couplings have good corrosion resistance.

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

Minimize leaks in your line—these fittings have a single barb that creates a smooth clamping surface for extra-tight connections.

Aluminum Low-Pressure Barbed
Tube Fittings for Air and Water

Aluminum fittings have good corrosion resistance, but are lighter in weight than brass.

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

Color-code fittings for easy identification. These aluminum fittings have good corrosion resistance, but are lighter in weight than brass.

Stainless Steel High-Pressure Barbed
Tube Fittings for Air and Water

Made of stainless steel, these fittings have better corrosion resistance than brass fittings.

Barbed Fittings for Plastic and Rubber Tubing—Chemicals

Barbed Fittings for Plastic and
Rubber Tubing—Chemicals

Fittings have a barb that grips onto tubing. Use in applications up to 120 psi.

Coupling Nuts

Low-Strength Steel Coupling Nuts

About half the strength of medium-strength steel coupling nuts, these nuts are for light duty fastening applications.

Medium-Strength Steel Coupling Nuts—Grade 5

Made from Grade 5 steel, these inch-sized coupling nuts are suitable for most applications.

High-Strength Steel Coupling Nuts—Grade 8

Made from Grade 8 steel, these nuts are about 25% stronger than medium-strength steel coupling nuts. Furnished in inch thread sizes.

18-8 Stainless Steel Coupling Nuts

These coupling nuts have good chemical resistance.

Super-Corrosion-Resistant 316
Stainless Steel Coupling Nuts

More corrosion resistant than 18-8 stainless steel coupling nuts, these nuts have excellent resistance to chemicals and salt water.

Brass Coupling Nuts

Brass coupling nuts are corrosion resistant in wet environments and electrically conductive.

Stainless Steel Extra-Long Coupling Nuts

Stainless steel coupling nuts have excellent corrosion resistance in most environments.

Round Coupling Nuts

A smooth rounded body provides a finished look.

Coupling Nuts with Sight Hole

Use the sight hole to check for proper thread engagement.

Thread Adapters

Inch-to-Inch Male-Female Hex Thread Adapters

Change thread sizes or types, such as fine to coarse threads, on parts without changing gender.

Inch-to-Metric Male-Female Hex Thread Adapters

Change inch threads to metric with these adapters, or swap metric threads for inch. An external hex lets you tighten or loosen them with a wrench.

Inch-to-Inch Female Hex Thread Adapters

Connect two differently sized male-threaded parts, such as threaded rods, and tighten with a standard wrench.

Left-Hand to Right-Hand Female Hex Thread Adapters

Often called sleeve nuts, these thread adapters fasten parts with right-hand threads to parts with left-hand threads.

Inch-to-Metric Female Hex Thread Adapters

Adapt threaded rods from inch to metric. These adapters connect two male-threaded fasteners, so you can change the gender of a mating part or increase or decrease its thread size. The hex-shaped body fits into the head of a standard wrench.

Inch-to-Inch Male Hex Thread Adapters

Need to join two female-threaded parts, such as coupling nuts, with dissimilar inch thread sizes? Attach them to these adapters and tighten the exterior hex nut for a secure connection.

Inch-to-Metric Male Hex Thread Adapters

One side inch, one side metric, and a hex in the middle—these handy fasteners connect two female-threaded parts, such as coupling nuts, adapting from inch threads to metric. Tighten with a standard wrench.

Rod Alignment Couplers

Increase cylinder life by fixing alignment problems between air or hydraulic cylinders and driven components.

Extension Spring Stud Anchors

Corrosion-Resistant Extension Spring Stud Anchors

These stainless steel anchor studs offer excellent corrosion resistance.

Extension Spring Stud Anchors

A black-oxide finish provides mild corrosion resistance.

Corrosion-Resistant Swiveling
Extension Spring Stud Anchors

These stainless steel anchor studs offer excellent corrosion resistance.

Swiveling Extension Spring Stud Anchors

A black-oxide finish provides mild corrosion resistance.

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.

Handles and Knobs

Create-Your-Own Push/Pull Control Cables

Pair these cables with a knob or lever to operate valves, throttle controls, and HVAC damper controls from a distance. They're flexible for weaving around obstructions.

Low-Friction Create-Your-Own Push/Pull Control Cables

A splined core limits contact points on the cable’s liner, so the core slides back and forth smoothly and keeps the cable from twisting. Pair these cables with a knob or lever to operate valves, throttle controls, and HVAC damper controls from a distance. They're flexible for weaving around obstructions.

Corrosion-Resistant Create-Your-Own
Push/Pull Control Cables

Well-suited for damp environments, these control cables have stainless steel fittings for excellent corrosion resistance. Pair them with a knob or lever to operate valves, throttle controls, and HVAC damper controls from a distance. They're flexible for weaving around obstructions.

Pull Control Cables

Similar to the brake cable on a bicycle, these cables exert pulling force so you can control components such as latches, release valves, and brakes.

Pipe and Pipe Fittings

Miniature Medium-Pressure StainlessSteel Threaded Pipe Fittings

Miniature Medium-PressureAluminum Threaded Pipe Fittings

Standard-Wall Plastic Pipe Fittings for Water

Plastic Pipe Fittings for Oil

Tube Fittings for Plastic and Rubber Tubing—Air and Water

Brass Push-to-Connect Tube Fittings for Air

Plastic Quick-Turn Tube Couplings for Air and Water

Stainless Steel Quick-Turn Tube Couplings for Air

Brass Quick-Turn Tube Couplings for Air

Tight-Seal Moisture-Resistant PlasticBarbed Tube Fittings for Air and Water

Aluminum Low-Pressure BarbedTube Fittings for Air and Water

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

Stainless Steel High-Pressure BarbedTube Fittings for Air and Water

Barbed Fittings for Plastic and Rubber Tubing—Chemicals

Barbed Fittings for Plastic andRubber Tubing—Chemicals

Coupling Nuts

Low-Strength Steel Coupling Nuts

Medium-Strength Steel Coupling Nuts—Grade 5

High-Strength Steel Coupling Nuts—Grade 8

18-8 Stainless Steel Coupling Nuts

Super-Corrosion-Resistant 316Stainless Steel Coupling Nuts

Brass Coupling Nuts

Stainless Steel Extra-Long Coupling Nuts

Round Coupling Nuts

Coupling Nuts with Sight Hole

Thread Adapters

Inch-to-Inch Male-Female Hex Thread Adapters

Inch-to-Metric Male-Female Hex Thread Adapters

Inch-to-Inch Female Hex Thread Adapters

Left-Hand to Right-Hand Female Hex Thread Adapters

Inch-to-Metric Female Hex Thread Adapters

Inch-to-Inch Male Hex Thread Adapters

Inch-to-Metric Male Hex Thread Adapters

Rod Alignment Couplers

Rod Alignment Couplers

Extension Spring Stud Anchors

Corrosion-Resistant Extension Spring Stud Anchors

Extension Spring Stud Anchors

Corrosion-Resistant SwivelingExtension Spring Stud Anchors

Swiveling Extension Spring Stud Anchors

Grease Fitting Adapters

Grease Fitting Adapters

Handles and Knobs

Create-Your-Own Push/Pull Control Cables

Low-Friction Create-Your-Own Push/Pull Control Cables

Corrosion-Resistant Create-Your-OwnPush/Pull Control Cables

Pull Control Cables

Miniature Medium-Pressure Stainless
Steel Threaded Pipe Fittings

Miniature Medium-Pressure
Aluminum Threaded Pipe Fittings

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

Aluminum Low-Pressure Barbed
Tube Fittings for Air and Water

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

Stainless Steel High-Pressure Barbed
Tube Fittings for Air and Water

Barbed Fittings for Plastic and
Rubber Tubing—Chemicals

Super-Corrosion-Resistant 316
Stainless Steel Coupling Nuts

Corrosion-Resistant Swiveling
Extension Spring Stud Anchors

Corrosion-Resistant Create-Your-Own
Push/Pull Control Cables