Peterson Fluid Systems Fitting 5/8-18 x 1/8 NPT Female

This fitting uses a 5/8-18 thread on one end and a 1/8 NPT female thread on the other. It's made from solid brass, which is a good choice for fluid fittings because it resists corrosion and holds up well to vibration. This part is commonly used in custom plumbing setups for oil or fuel systems, especially when you need to adapt between different thread types.

Peterson Fluid Systems is known for making parts for high-performance oil systems, so you can expect this fitting to be well-made. It's a straightforward piece that does its job connecting two different threaded components reliably. If you're building a custom oil or fuel line and need to step down from a 5/8-18 male fitting to a 1/8 NPT female port, this is the adapter you'll need.