NPT

NPT stands for National Pipe Taper and is a tapered machine thread for threaded pipes and fittings. NPT fittings are perfect for fluid fittings like oil lines, brake lines, and coolant lines. The threads on NPT fittings are tapered, creating an interference fit. Thread tape or sealant will form a tight liquid seal without requiring the use of O-rings, gaskets, or crush washers.