Brass Twist Lock Air Line Coupler Fittings — 3-Way Push-to-Connect Quick Connector, 4–12mm Tube

Match the fitting size to your tube's outer diameter (OD). For example, a 6mm fitting accepts 6mm OD tubing. If you're working with imperial tubing, 1/4" OD is approximately 6.35mm — in most cases a 6mm fitting will work, but confirm with a caliper before ordering. When in doubt, select the size closest to your tube OD.

Brass push-to-connect fittings of this type generally handle working pressures up to approximately 150 PSI (≈10 bar) in standard pneumatic applications. Contact us to confirm the rated pressure for the specific size you need before use in high-pressure or safety-critical circuits.

Brass offers good natural corrosion resistance and is generally suitable for moderately humid or damp indoor environments. For prolonged outdoor exposure or contact with aggressive chemicals, additional sealing or a protective coating is recommended. In most cases, these fittings perform well in typical workshop or garage conditions.

These fittings are designed for metric OD tubing (4mm, 6mm, 8mm, 10mm, 12mm). They are compatible with standard pneumatic polyurethane (PU), nylon (PA), and polyethylene (PE) tubing of the corresponding outer diameter. Always confirm your tube's OD before ordering — inner diameter (ID) is not the relevant measurement here.

No tools are required for tube insertion. Simply push the tube in firmly until it seats and twist to lock. To release, twist and pull. No thread tape is needed for the push-in tube ports. If the fitting has a threaded body port, use PTFE tape on that thread as standard practice.

The 3-way design typically provides a T-shaped flow path, allowing one inlet to split into two outlets — or two lines to merge into one. This is commonly used to branch a single compressed air supply into two separate tool circuits without needing an additional tee adapter.

Yes. Twist lock push-to-connect fittings are generally designed for repeated connect/disconnect cycles. The internal collet and O-ring seal are reusable in most cases. Performance may degrade over many cycles or if the tube end is cut unevenly — always use a clean, square-cut tube end for best results.