A stainless weld-in bung giving a male AN10 flare port. AN10 handles serious volume, which is why it is used on oil cooler and scavenge lines, dry sump plumbing, turbo drains, high-capacity fuel feeds and breather runs. Stainless is worth the extra spend when the host vessel is stainless, or the port is exposed to heat, moisture or coastal air and you want it to stay serviceable for the life of the build. Weld with matching stainless filler and keep heat input under control, since a large port distorts more easily than a small one. Fit the mating AN10 hose end without thread sealant and avoid over-tightening the flare.