A steel weld-in bung creating a male AN12 port. AN12 is a large-volume size used for dry sump scavenge lines, oil cooler plumbing, crankcase breathers and vents, and high-capacity fuel or surge tank connections where a smaller port would choke flow. Steel welds readily into mild steel tanks, fabricated sumps, chassis members and mounting plates using MIG or TIG, making it the cost-effective option on steel-bodied builds. Weld the full circumference and work in stages to keep the heat spread out, since a large port is prone to distortion. The mating AN12 hose end seals on the 37-degree flare, so no thread tape or sealant is needed.