Stainless Steel Swagelok Tube Fitting, Male Connector, 1/4 in. Tube OD x 3/8 in. Male NPT

The Swagelok SS-400-1-6 connects 1/4 in. tube to a 3/8 in. male NPT port in a single 316 stainless body. It is the fitting you grab when the tubing and the port refuse to be the same size.

Adapting across one pipe size with a bushing works right up until the bushing seeps, and then you are chasing a leak through a joint you added yourself. A purpose-built connector gives you one tube seal and one pipe thread, nothing hidden behind it.

The tube end is a genuine gaugeable Swagelok two-ferrule connection. The back ferrule grips and supports the tube while the front ferrule seals, and an inspection gauge proves the pull-up before startup. Collins-Oliver stocks it in Baton Rouge for same-day pickup. Call (800) 247-5756.