Product details:

Eldon James 1/4-19 BSP to 3/8" Barbed Adapter, Glass Filled Black Nylon BSPT threads have on the Whitworth thread form, which is designed to provide a pressure-tight fit through mating of the threads. This is accomplished by cutting the threads on a taper. Because they are tapered, the thread can only screw into the companion female thread a certain distance before it jams. The standard specifies this distance as a length based on hand-tight engagement; a convenient rule-of-thumb for plastic threads is: finger-tight plus 1/2 to 1 turn with a wrench. Do not over-tighten plastic threads stress on the fitting can result in its failure. Features: Standard material in automotive and marine under-the-hood, heater and coolant applications. Enhanced impact resistance results from inclusion of uniformly dispersed glass fibers that add strength to the resin: automotive industry approvals. Temperature Range -50 F to 275 F (135 C). Pressure 150 psi at 70 F Heat Deflection Temperature - ASTM D64: 475 F (246 C) at 264 psi