The Rockwell B scale is a method used to measure the hardness of materials, particularly metals. It employs a specific indenter, typically a 1/16-inch steel ball, which is pressed into the material's surface under a predetermined load. The hardness value is determined by the depth of the indentation left after the load is removed, with a higher number indicating a harder material. This scale is part of the broader Rockwell hardness test, which includes various scales for different materials. The Rockwell B scale is particularly useful for softer metals, such as aluminum and copper alloys, providing a quick and reliable assessment of their hardness.