The extended-body steel AN10 weld bung. AN10 is a high-flow size, used for oil cooler and scavenge lines, dry sump plumbing, turbo drains, big fuel feeds and breather runs where restriction is the enemy. The long body earns its place when the port must pass through a thick steel tank wall, a boxed chassis section or a recessed panel, standing the thread proud so you can get a spanner onto the hose end. It also keeps the 37-degree flare seat away from welding heat, reducing the risk of distorting the sealing surface. Weld fully around into mild steel, then fit any AN10 hose end without sealant.