This straight adapter mates an AN10 37-degree male flare to a 1/2″ NPT male pipe thread, one of the most-used combinations in performance plumbing. The 1/2″ NPT side threads into pumps, filter heads, cooler bodies, sump bungs and adapter plates that were tapped in pipe thread, while the -10 AN side takes a standard hose end for oil cooler, dry sump or high-volume fuel work. NPT is a tapered thread that seals by interference, so apply a fuel-safe thread sealant or PTFE tape, starting a thread or two back, and tighten until snug rather than overtightening into thin castings. The AN flare needs no sealant at all.