Brass Compression Cross Fitting 4-Way Flared Connector — 6mm & 8mm

Match the fitting size to your tubing's outer diameter (OD). Select the 6mm option for tubing with a 6mm OD — that's approximately 1/4" — and the 8mm option for 8mm OD tubing (approximately 5/16"). The 6×6×8×8mm reducer cross is typically used when you need to connect two 6mm lines to two 8mm lines at a single junction. When in doubt, measure your tubing OD with calipers before ordering.

Brass compression fittings of this type generally support working pressures in the range of 150–300 PSI depending on tubing material, wall thickness, and installation quality. For exact pressure ratings specific to your application, please contact us to confirm before use in high-pressure systems.

Brass offers good corrosion resistance in most indoor and mild outdoor environments. It is generally not recommended for highly saline, acidic, or ammonia-rich conditions. For harsh outdoor, marine, or chemical-exposure applications, stainless steel fittings are typically a better choice.

These fittings are typically compatible with semi-rigid and rigid tubing including nylon, polyurethane (PU), polyethylene (PE), and copper tubing with matching outer diameters. Always verify that your tubing OD matches the selected fitting size for a secure, leak-free compression seal.

In most cases, only a standard wrench is needed to tighten the compression fitting — no soldering, flux, or heat required. Ensure the tubing end is cut cleanly and squarely before insertion. A tube cutter is recommended over a utility knife for the cleanest, most leak-resistant cut.

The 6×6×8×8mm designation indicates a reducer cross fitting with two 6mm ports and two 8mm ports arranged in a cross (4-way) configuration. This allows you to branch or merge lines of two different diameters at a single junction point — useful when your system transitions between tubing sizes.

Multi-packs are ideal for larger system builds, multi-branch installations, or keeping spares on hand for maintenance. Ordering a 3-pack or 5-pack generally reduces the per-unit cost and ensures you have replacements available without waiting for a reorder when a fitting needs servicing.