Stainless Steel Compression Fittings
Ideal for installations where secure, leakproof joints are essential, BES stocks a wide range of stainless-steel compression fittings, best suited for high pressures, vacuums, and applications with inherent vibration. These fittings are precisely machined to close tolerances.
Shop now for speedy delivery of elbow, straight, tee and all stainless-steel compression fitting types with BES.
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Every Type Of Stainless Steel Compression Fitting For The Job
Whether working on a small domestic project that requires a 6mm compression fitting or a more extensive commercial system that relies on high-quality tube couplings, we’ll have stainless steel fittings in stock if needed. Our range of stainless steel compression fittings includes:
Male Stud Couplings
Male stud couplings connect stainless steel tube to equipment, valves, manifolds or other components with a female threaded port. They are available with BSP parallel and BSP taper male threads, making them useful when converting a compression tube connection to a threaded system connection. Our options include the 15mm x 1/2" BSP taper male stud coupling and 12mm x 1/2" BSP taper male stud coupling.
Stainless Steel Elbows
Compression elbows change the direction of a tube run, normally through 90°, without bending the tube immediately beside the connection. Choose an equal compression elbow such as the 8mm stainless steel elbow, or use a threaded stud elbow such as the 6mm x 1/8" BSP taper male stud elbow when the tube must turn as it connects to a threaded port.
Female Stud Couplings
Female stud couplings adapt stainless steel tube to a male BSP connection on a valve, instrument or other threaded component. They provide a compact transition between compression tube and female parallel thread without the need for a separate adaptor. Our selection includes options such as the 15mm x 1/2" BSP parallel female stud coupling and the 1/2" x 1/2" BSP parallel twin-ferrule female stud coupling.
Straight Couplings
Straight couplings join two sections of tube in line and are commonly used to extend a run, replace a damaged section or create a demountable connection. Equal couplings join tubes of the same outside diameter, while reducing versions can connect selected imperial tube sizes. Our metric range includes products such as the 6mm stainless steel straight coupling and 12mm stainless steel straight coupling.
Bulkhead Couplings
Bulkhead couplings carry a tube connection securely through a panel, cabinet wall or enclosure. The threaded centre section allows the fitting to be fixed in position, helping prevent movement where tubing passes between separate areas of an installation. Popular options include the 15mm stainless steel bulkhead coupling or the imperial twin-ferrule 1/2" stainless steel bulkhead coupling.
Stainless Steel Tees
Equal compression tees create a branch from an existing tube run while maintaining the same outside diameter across all three connections. They are useful for dividing a flow, adding an instrument line or extending a system in two directions. Available metric options include the 8mm stainless steel tee and 12mm stainless steel tee. Plan the tube alignment carefully so that all three connections enter the fitting squarely without placing strain on the branch.
Stainless Steel Caps
Compression caps close the end of a tube while retaining the option to extend or alter the system later. They can be useful during testing, phased installation, maintenance or when an unused tube end needs to be isolated. Our imperial twin-ferrule range includes the 1/2" stainless steel cap and 1" stainless steel cap.
Front Ferrules
Our replacement sizes include options such as the 3/8" stainless steel front ferrule and 5/16" stainless steel front ferrule. Ferrules should not be mixed between incompatible fitting designs or manufacturers.
Stainless Steel Compression Nuts
Compression nuts draw the ferrule assembly into the fitting body as the joint is tightened. They are useful as replacement components where the original nut has been lost or damaged, but they must match the fitting system and tube size exactly. We offer options such as the 1/2" stainless steel compression nut and 1" stainless steel compression nut.
Stainless Steel Plugs
Compression plugs blank an unused fitting port rather than closing the end of a tube. They are useful for temporarily or permanently isolating spare branches, instrument connections and unused positions in a manifold or installation. Our range includes options such as 3/8" stainless steel compression plug and 1" stainless steel compression plug.
Rear Ferrules
The rear ferrule in a twin-ferrule assembly helps grip and support the tube as the nut is tightened. Used with the front ferrule, it helps distribute the mechanical load rather than relying on one component to perform both gripping and sealing functions. Replacement options include the 1/2" stainless steel rear ferrule and 1/4" stainless steel rear ferrule.
Single Ferrules
Single ferrules combine the tube-gripping and sealing functions within one component. Individual replacements include the 6mm stainless steel single ferrule and 28mm stainless steel single ferrule. Match the ferrule to the tube outside diameter and the corresponding fitting body; an imperial ferrule must not be selected for a nominally similar metric tube.
Bulkhead Connectors
Bulkhead connectors pass a tube connection through a panel and terminate in a male or female BSP thread on the other side. They are useful for connecting internal tubing to an external valve, hose, instrument or threaded pipework while keeping the panel connection secure. Choose between fittings such as the 1/2" stainless steel bulkhead male connector and 1/4" stainless steel bulkhead female connector.
How To Choose The Correct Stainless Steel Compression Fitting
Start with the tube outside diameter. A 12mm compression connection is designed for tube with a 12mm outside diameter, while a 1/2" compression connection accepts tube with a 1/2" outside diameter. These measurements do not describe the internal bore of the tube.
Where a fitting also has a threaded connection, read the two sizes separately. For example, a 15mm x 1/2" BSP male stud coupling joins 15mm outside-diameter tube to a 1/2" BSP threaded port. Also check whether the BSP connection is parallel or taper, as the thread form and sealing method are not interchangeable.
How To Install Stainless Steel Compression Fittings
Correct tube preparation and controlled tightening are essential to a reliable compression joint. Because our selection includes different single- and twin-ferrule designs, follow the instructions for the exact fitting rather than applying one universal number of turns or tightening torque.
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Check the components. Confirm the tube outside diameter, wall thickness, material and fitting type. Do not mix nuts, ferrules or bodies from incompatible systems.
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Cut the tube squarely. Use a suitable stainless steel tube cutter or fine-tooth saw without crushing or distorting the tube.
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Deburr and clean the tube. Remove internal and external burrs, swarf, grease and contamination. Check that the sealing area is round and free from deep scratches.
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Fit the components in the correct order. Where loose components are used, install the nut and ferrule or ferrules in the specified orientation.
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Insert the tube fully. Push the tube into the fitting until it reaches the internal shoulder. A tube that has not bottomed correctly may produce an unreliable joint.
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Tighten as instructed. Hold the fitting body steady with one spanner and tighten the nut with a second correctly sized spanner. Follow the fitting manufacturer’s first-make and remake instructions.
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Inspect and test. Check tube alignment and support before carrying out the appropriate pressure or leak test. Never loosen, tighten or dismantle a fitting while the system is pressurised.
Typical tools include a tube cutter or suitable saw, internal and external deburring tools, a marker, measuring equipment, and two correctly sized spanners. System-specific inspection gauges or assembly equipment may also be required. Manufacturer guidance on tube fittings emphasises correct preparation, full tube insertion, and adherence to the specified assembly procedure.
Compression Fittings Delivered In No Time
If you’re a frequent buyer, we highly recommend requesting the latest edition of the BES catalogue, and using Quick Shop. You simply tell us the product item code & quantity, and it’s added to your basket for speedy delivery.
If you need assistance ordering stainless steel fittings, or have a question about a product, get in touch by phoning free on 0800 80 10 90.
FAQs
How do I determine the correct compression fitting size?
Measure the outside diameter of the tube, not its internal bore. Metric fittings are selected in millimetres and imperial fittings in fractions of an inch. Where a product has a second BSP measurement, that figure describes the threaded connection rather than the tube size.
What is the difference between single- and twin-ferrule fittings?
A single-ferrule fitting uses one ferrule to grip and seal around the tube. A twin-ferrule fitting has separate front and rear ferrules, distributing sealing and gripping functions between the two components.
Are stainless steel compression fittings reusable?
Some compression fittings can be disconnected and remade when the manufacturer’s instructions permit it. Reassembly normally requires the same correctly swaged tube end and ferrules to be returned to their previous position. Do not reuse damaged, distorted or contaminated components, and never dismantle a pressurised connection.
How tight should a stainless-steel compression fitting be?
Tighten it according to the fitting manufacturer’s assembly instructions. The correct movement from finger-tight differs between fitting designs and sizes, so applying a generic turn count or simply tightening until the joint “feels tight” can result in under- or over-assembly.
Can I mix stainless steel compression fitting components?
Nuts, ferrules and fitting bodies should be treated as parts of a complete fitting system. Do not mix components merely because their nominal sizes or threads appear similar, as differences in geometry, tolerances and assembly requirements can affect the joint.