A steel weld-in bung creating a male AN16 port in steel fabrications. AN16 is the size for high-volume, low-pressure work: coolant and header tank plumbing, crankcase breathers and vents, dry sump reservoir connections and large fuel transfer lines. Steel welds well into mild steel tanks, fabricated sumps, chassis sections and mounting plates with MIG or TIG, and keeps costs down where corrosion is not a concern or the area will be painted. Weld the full circumference in stages so the heat does not warp a port this large. The mating AN16 hose end seals on the 37-degree flare, so leave sealant off the thread.