Compression fitting Barrow THKN-3/8-V4 b, 16/10 (3/8 inch OD x 10mm ID), black

Barrow THKN-3/8-V4 b is a compression fitting designed for PC liquid cooling systems. Sized 16/10 (3/8" outer diameter, 10 mm inner diameter) and finished in black, this fitting provides a threaded compression connection to securely join soft tubing to other fittings, water blocks, or radiators. The fitting is intended for standard soft tubing used in custom cooling loops and aims to create a tight, leak-resistant seal where tubing meets barbs or port threads.

Advantages

The compression design reduces the need for additional clamps while maintaining reliable tube retention. Its black finish offers a neutral, unobtrusive appearance that integrates with a wide range of case and component colors. The fitting's dimensions match common 16/10 soft tubing, ensuring compatibility with many aftermarket tubes and simplifying installation in custom water-cooling builds.

Suitable for

• Custom PC water-cooling loops using 16/10 (3/8" OD x 10 mm ID) soft tubing
• Connecting tubing to radiators, pumps, reservoirs, and water blocks
• Upgrading or replacing existing compression fittings in a liquid-cooling system

Key specifications

• Tubing outer diameter: 3/8" (approx. 9.5–10 mm)
• Inner diameter compatibility: 10 mm soft tubing
• Finish: black
• Connection type: threaded compression for soft tubing
• Material: metal body with sealing components (designed for liquid-cooling use)

How to use

Ensure the tubing end is cut cleanly and square. Slide the compression nut (if separate) onto the tubing, push the tubing firmly onto the mating barb or port until seated, then thread the compression fitting onto the port and tighten by hand before a final slight turn with a wrench to secure the seal. Do not overtighten, as excessive force can damage threads or deform tubing. After installation, inspect joints and run the cooling loop with the system filled and pressurized at low pump speed to check for leaks.

Recommendations

Use the fitting with compatible 16/10 soft tubing and standard liquid-cooling components. Replace sealing components if worn and perform a leak test after any maintenance or reconfiguration. Avoid using incompatible rigid tubing types that do not match the stated inner diameter.