SS: Stainless Steel: Stainless steel contains more chromium than ordinary steel . It is often called corrosion-resistant steel because it does not stain, corrode or rust as readily as ordinary steel. It has a high shine and lasts longer.
NP: Nickel Plated: Used over malleable Iron or Zinc Die Casting to give a smoother, shiny surface to the metal. Does not rust as readily as ordinary iron, but does not last as long as Stainless Steel.
SB: Solid Brass: The most durable and one of the most popular of materials. Very strong and will not rust. A little more expensive, but worth the extra price.
BP: Brass Plating: Used over malleable Iron or Zinc Die Casting to give a smoother, shiny surface to the metal. Does not rust as readily as ordinary iron, but does not last as long as Solid Brass.
MI: Malleable Iron: Often used for casting small items such as buckles and snaps. By itself, it would rust almost imediately. Usually covered with Brass, Nickel, or Zinc to enhance appearance and retard rust. Malleable iron pieces will rust when the plating is chipped or worn off.
DC: Die Cast: Some smaller items are cast from zinc. Usually the least expensive in a group, die cast items tend to be more brittle than malleable iron and have a shorter life.