Stainless steel plugs
Stainless plugs consist of a zero volume nut with a ferrule made up on a solid rod.
For high pressure applications such as SFE and SFC (>7000 psi) use the special high pressure plugs, with the ferrule and rod machined as a single, solid piece.
Stainless steel caps
A cap is essentially a piece of hex stock with a zero volume fitting detail machined into it, but with no through hole.
