Best Tube Fitting Adapters of 2026

Tom Law Avatar
Tom Law
Last Updated: 2 Feb 2026

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Tube fitting adapters are essential components used in the installation and connection of tubing systems. These adapters are designed to facilitate secure and leak-proof connections between tubes of different sizes, shapes, and materials. They are widely used in various industrial applications such as oil and gas, chemical processing, and food and beverage processing. Tube fitting adapters come in different materials such as stainless steel, brass, and plastic, and are available in a variety of configurations to suit specific requirements. These adapters are highly recommended for their reliability, durability, and ease of use.

At a Glance: Our Top Picks

John Guest 3/8" Push-in Female Adaptor Cover #TOP 1
John Guest 3/8" Push-in Female Adaptor
ftb score rating icon 9.8
John Guest 3/8 Inch Straight Tube Adaptor Cover #TOP 2
John Guest 3/8 Inch Straight Tube Adaptor
ftb score rating icon 9.7
John Guest Female Adaptor 3/8 inch Tube to FFL Thread Cover #TOP 3
John Guest Female Adaptor 3/8 inch Tube to FFL Thread
ftb score rating icon 9.5

Top 5 Tube Fitting Adapters

#TOP 1

John Guest 3/8" Push-in Female Adaptor

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Klein
John Guest 3/8" Push-in Female Adaptor Cover
JOHN GUEST - 3/8" OD TUBE X 3/8" BSP FEMALE ADAPTOR - BSPP Thread, Flat End (Push-in Fittings, Imperial)

The John Guest Female Adaptor is designed for easy use with push-in fittings, making it perfect for quick connections in various applications. Its BSPP thread ensures a secure fit, preventing leaks and providing peace of mind. The flat end design allows for straightforward installation, saving you time and effort. With a 3/8" outer diameter, this adaptor is versatile and compatible with a range of tubes, ensuring you can tackle your fitting needs with confidence.

What We Like
Easy push-in fitting
Secure BSPP thread
Flat end for simple installation
Versatile 3/8" diameter
#TOP 2

John Guest 3/8 Inch Straight Tube Adaptor

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Gray
0.375 inches
John Guest 3/8 Inch Straight Tube Adaptor Cover
John Guest Straight Adaptor 3/8 inch Tube OD x 3/8 inch BSP Male Thread (one Supplied)

The John Guest Straight Adaptor offers a simple and effective way to connect 3/8 inch outer diameter tubing to a 3/8 inch BSP male thread. Made from durable gray acetal copolymer, this adaptor ensures a reliable and long-lasting connection, resistant to wear and tear. The straight design allows for easy alignment in your plumbing or fluid systems, making installation straightforward and convenient. With the John Guest Straight Adaptor, you can expect a secure fit that helps maintain system integrity and performance.

What We Like
Durable acetal copolymer material
Easy to connect tubing and threads
Straight design for simple alignment
Suitable for 3/8 inch tube and thread
#TOP 3

John Guest Female Adaptor 3/8 inch Tube to FFL Thread

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John Guest Female Adaptor 3/8 inch Tube to FFL Thread Cover
John Guest Female Adaptor 3/8 inch Tube OD x 3/8 FFL Thread (one Supplied)

The John Guest Female Adaptor is ideal for connecting different types of pipes or fittings, making your plumbing tasks much easier. Its push-to-connect fitting lets you quickly attach pipes or tubing on one side, while the other end features a flared female NPT connector, providing a secure and versatile connection. Made from durable acetal copolymer plastic, it resists moisture and offers strong mechanical performance, so you can rely on it for long-lasting use. With a working pressure of up to 150 psi, you can confidently use this adaptor in various household or commercial applications.

What We Like
Easy pipe connection
Push-to-connect design
Durable plastic material
Handles high pressure
#TOP 4

John Guest Straight Adaptor for Tube and Thread

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Gray
John Guest Straight Adaptor for Tube and Thread Cover
John Guest Straight Adaptor 3/8 inch Tube OD x 1/4 inch BSPT Male Thread

The John Guest Straight Adaptor is designed for connecting a 3/8 inch tube to a 1/4 inch BSPT male thread. Its robust gray acetal copolymer construction ensures durability and reliability in various applications. This feature is particularly useful for maintaining a secure connection, providing peace of mind during use. With its straightforward design, you can easily install it in your projects, saving you time and effort. Whether you're working in plumbing or other fluid-related tasks, this adaptor offers a practical solution for your fitting needs.

What We Like
Durable acetal copolymer material
Easy installation process
Secure connections
Versatile for various applications
#TOP 5

sourcing map G1/2 Female Thread Compression Adapter

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Copper
sourcing map G1/2 Female Thread Compression Adapter Cover
sourcing map Compression Tube Fitting G1/2 Female Thread x 6mm Tube OD Straight Coupling Adapter Brass

The sourcing map Compression Adapter features a G1/2 female thread size, making it ideal for connecting to 6mm tubing. Its robust brass construction ensures that it is rustproof and resistant to corrosion, providing durability for various applications. This fitting allows you to convert G thread pipes to straight compression thread pipes, offering versatility in your plumbing projects. Additionally, it is suitable for use with multiple types of tubing, such as copper, brass, and plastic, making it a convenient choice for your needs.

What We Like
Durable brass construction
Rustproof and corrosion resistant
Versatile for various tubing types
Easy conversion of pipe types
Buying Guide Image

Frequently Asked Questions (FAQs)

1. What is a Swagelok tube fitting?

Swagelok's flagship product is our tube fitting, designed to provide a leak-tight seal for pressures up to the suggested allowable pressure rating of the tubing. It is a two-ferrule, mechanical-grip, hinging-colleting type connection consisting of a fitting body, a nut, a front ferrule, and a back ferrule.

2. How many types of tube fittings are there?

Threaded fittings come in two distinct varieties: those with straight or parallel threads, and those with tapered threads. Straight threads are designed to hold a nut onto the body of a tube fitting and rely on supplemental items, including gaskets, O-rings, or metal-to-metal contact to create a leak-tight seal.

Editor's Notes

During our tube fitting adapter research, we found 306 tube fitting adapter products and shortlisted 5 quality products. We collected and analyzed 2,982 customer reviews through our big data system to write the tube fitting adapters list. We found that most customers choose tube fitting adapters with an average price of £20.00.

The tube fitting adapters are available for purchase. We have researched hundreds of brands and picked the top brands of tube fitting adapters, including John Guest, sourcing map.

Written by
Tom Law Avatar

Tom Law is an adventurer who has captured his love for nature into all of his works. A native of Newcastle, Tom has always wanted to share beautiful stories alongside the lovely sights of nature. Fortunately, he took into photography on one of his many journeys and gradually grew a passion for it. Tom Law is now an expert photographer who tours the world while creating and keeping memories of his adventures. He frequently puts his thoughts and experiences into writing.