A straight AN6 to 1/4″ NPT adapter, used to bring an AN6 line into a component that has been tapped with 1/4″ NPT pipe thread. AN6 is the workhorse size for fuel feed and return on most road and club-level race builds, as well as oil gauge and turbo feed runs, so this is one of the adapters you reach for most often. The AN end seals on its 37-degree flare cone and needs no sealant. The 1/4″ NPT end is a tapered pipe thread and does need PTFE tape or a liquid thread sealant on the male threads to seal properly. Wind it in until snug, then a small further turn to clock the fitting – do not lean on it, as over-tightening a taper thread can split a cast or alloy housing.