NPT FITTINGS
NPT fittings use a tapered thread standard (National Pipe Thread) common on fuel, oil and coolant lines, gauges and fittings in automotive and race applications. The taper means the fitting seals as it's tightened, rather than relying on a separate flat gasket.
When choosing an NPT fitting, match the thread size to the port you're fitting into and check whether you need male or female, straight or angled, to suit the hose or line you're connecting.
Frequently asked questions
What makes NPT different from other thread types?
NPT threads are tapered, so they seal by wedging tight as you screw them in, rather than needing a separate sealing washer or flat gasket like some other thread standards.
Do I need thread sealant with NPT fittings?
Most NPT fittings are sealed with thread tape or a liquid sealant applied to the male thread before assembly, since the taper alone can still allow small leaks without it.
