Mechanical outside micrometers have a C-shaped jaw with flat measuring faces on the anvil and spindle. The anvil is stationary, while the spindle moves when the thimble on the body is turned. They have no battery or electronic components that could be damaged by heat or exposure to liquids or particles. These micrometers are commonly used to measure the outside dimensions of raw materials, whole workpieces, and features in production, QA, and inspection environments in both metalworking and other industrial applications.