5/8-18 RH Tube End - 1-1/4in x .065in

The 5/8-18 RH Tube End - 1-1/4in x .065in from MEZIERE is a precision weld-on threaded connector engineered for high-performance cooling system fabrication and custom tube assembly work. This right-hand female thread fitting serves as a critical junction point in radiator hose lines, engine coolant circuits, and custom hot rod or race car cooling configurations where reliability and leak-free operation are non-negotiable. Designed for builders and shops that demand OEM-grade component integrity, this tube end accommodates 1-1/4 inch diameter tubing with 0.065 inch wall thickness—a specification common in medium-duty automotive and marine cooling applications.

Manufactured from chromoly steel in its natural finish, the 5/8-18 RH Tube End delivers superior strength and durability in high-temperature and high-pressure environments. The weld-on design eliminates the need for compression fittings or clamps at the tube junction, creating a permanent, structurally unified connection that resists vibration-induced loosening and corrosion over extended service life. The 5/8-18 right-hand female thread accepts standard metric and SAE male connectors, providing compatibility with industry-standard hose barbs, bulkhead fittings, and coolant bypass blocks. Chromoly construction ensures thermal stability and resistance to coolant degradation, making this fitting suitable for both street and competition builds where consistent coolant flow is essential.

This tube end is ideal for custom cooling system builders, restoration shops, and motorsport fabricators assembling bespoke cooling circuits on vintage and modern performance vehicles. Installation requires TIG or MIG welding to the tube OD, making it a permanent solution for fixed-position radiator, water pump, and heater core connections. The compact 1.55 x 1.45 x 3.95 inch envelope and 0.32 lb weight make it lightweight and easy to position during welding operations. Compatible with 1-1/4 inch tubing wall thicknesses up to 0.065 inches, this MEZIERE fitting is essential for builders seeking OEM-quality cooling components without the expense of full-assembly replacement.