Micrometre parts and functions

 The  main parts of an outside micrometre

A micrometre is a precision instrument used to measure a job, generally within an accuracy of 0.01mm.Micrometers used to take the outside measurements are known as outside micrometers. The parts of a micrometer are listed here.

Frame

The frame is made of drop forged steel or malleable cast iorn. All other parts of the micrometre are attached to this.

Barrel/sleeve

The barrel or sleeve is fixed to  the frame. The datum line and graduations are marked on this.

Thimble

On the bevelled surface of the thimble also, the graduation is marked. The spindle is attached to  this.

Spindle

One end of the spindle is the measuring face. The other end is threaded and passes through a nut.. The treaded mechanism allows for the forward and backward movement of the spindle.

Anvil

The anvil is one of the measuring faces  which is fitted on the micrometre frame. It  is made of alloy steel and finished to a perfectly flat surface.

Spindle lock nut

The spindle lock nut is used to lock the spindle at a desired position

Ratchet stop

The ratchet stop ensures a uniform pressure between the measuring surfaces.