Review on Fleetguard Head Fuel Filter Part by Joshua Douglas

Just bought 6 of these for our boat. I was expecting 1/2" NPT but it's not. I haven't really figured out what the thread is yet, I just know nothing will fit in Home Depot. 1/2" NPT is very loose and does not tighten. . I think I'll go to Napa or somewhere else to try and find out. PITA safe as all fittings were already purchased with 1/2" NPT threads. UPDATE: The NAPA guy identified it as a 5/8 in. ORB (O-ring). So head to the hydraulic store for adapters too A hydraulic engineer confirmed the ORB 5/8" thread size. So I bought 12 5/8" ORB 1/2" NPT fittings so all my existing fittings would work. Bottom Line: The inlet/outlet fittings are NOT 1/2"NPT, they are 5/8"ORB.