Which antimony alloys are used to make pewter and britannia metal?

Antimony is used as an alloying agent to harden and strengthen tin, which is the primary component of both pewter and britannia metal.12

Composition of the Alloys

• Pewter: Modern pewter is a high-tin alloy typically composed of approximately 91 percent tin, 7.5 percent antimony, and 1.5 percent copper. While historical pewter often contained lead, modern formulations exclude it to ensure safety for use with food and drink. The addition of antimony, along with bismuth, provides the alloy with increased durability and a brighter sheen.32
• Britannia Metal: This alloy is composed of approximately 93 percent tin, 5 percent antimony, and 2 percent copper. It is similar in appearance to pewter but is generally harder, stronger, and more ductile, making it well-suited for spinning on a lathe or working from sheets.4

Both alloys are primarily used to manufacture domestic utensils, such as teapots, jugs, and drinking vessels.43