Swagelok 4FK0 Medium Pressure Stainless Steel Tube Fitting

Swagelok 4FK0 is a 316 stainless steel medium‑pressure tube fitting from the FK series, configured as a male connector for 1/4 in. tubing with a 1/2 in. male NPT thread. It utilizes Swagelok’s two‑piece FK design—a female body paired with a preassembled cartridge containing the nut and ferrules—delivering reliable, repeatable assemblies with standard Swagelok ferrules. This configuration is manufactured in 316 stainless steel and is part of Swagelok’s FK medium‑pressure fittings catalog, which also lists other alloys for different sizes, including alloy 2507 and alloy 625. These fittings are commonly used in oil and gas, chemical processing, and general process fluid systems that require robust stainless‑steel tube connections at medium pressure. Swagelok supports hydrostatic test data for medium‑pressure FK fittings, with documented tests for configurations in the 4FK0 family (such as SS‑4FK0‑1‑4) to validate performance under pressure.