an “AF 3/8NPT to 5/16 Str Barb blk” is a black-finished, straight adapter fitting used to connect a component with a 3/8-inch male NPT threaded port to a 5/16-inch rubber hose. It is a product from the company Aeroflow (AF), often used in automotive applications for fuel, vacuum, and coolant lines.Â
Component breakdown
AF: Abbreviation for the manufacturer, Aeroflow.
3/8NPT: The threaded end of the adapter is a 3/8-inch Male National Pipe Taper (NPT). This is a standard for threaded pipes and fittings.
5/16 Str Barb: The other end of the adapter is a 5/16-inch straight (Str) hose barb. A barb is a series of ridges that provides a tight seal and grip when a rubber or flexible hose is pushed over it.