What are the parts of micrometer caliper and their functions?

Answer 1

Frame, Anvil, Spindle, Spindle lock, Barrel, Thimble, and Rachet. <--NovaNet!!
spindle
spindle
An outside micrometer consists of the following parts:

• Frame - The body of the instrument.
• Sleeve - Contains the vernier and scales, also houses the spindle nut and thimble assembly.
• Thimble - Houses the adjusting nut, ratchet and screws over the spindle nut. The thimble and sleeve assembly enables the actual opening and closing of the instrument over the work piece to enable measuring.
• Spindle - Attached to the thimble and protrudes through the frame. Together with the opposite anvil the workpiece is measured between the spindle and anvil faces.
• Ratchet knob - Used to close the micrometer over the workpiece to measure it.
• Lock - Used to lock the spindle when a measurement is achieved before removing the instrument from the workpiece.
• Vernier and scale - This is imprinted on the sleeve and spindle and is what gives the actual measurement.