5160 is a designation for a type of steel commonly used in the production of swords, knives, and other bladed tools. It refers to a specific steel alloy composition and is often referred to as 5160 spring steel.

The numbers in "5160" represent the steel's approximate composition. In the case of 5160, it is generally composed of the following elements:

• 51: Indicates that the steel contains approximately 0.51% carbon. Carbon content significantly affects the hardness, strength, and edge retention of the steel.
• 60: Indicates that the steel contains approximately 0.60% chromium. Chromium is added to improve hardenability and increase the steel's resistance to wear and corrosion.

In addition to carbon and chromium, 5160 steel may contain trace amounts of other elements like manganese, silicon, and traces of other alloying elements. The specific composition may vary slightly depending on the manufacturer or supplier.

5160 steel is known for its toughness, durability, and excellent resilience. It is a popular choice for applications that require a combination of high strength, impact resistance, and the ability to withstand repeated stress, such as springs and blades. Its properties make it well-suited for use in swords, knives, and tools where toughness and durability are essential.

It's worth noting that the properties and performance of 5160 steel also depend on factors such as heat treatment, forging techniques, and the overall design and construction of the blade. Skilled craftsmanship and proper heat treatment play crucial roles in realizing the potential of 5160 steel for a specific application.