Micrometer

The micrometer is a precision measuring instrument, used by engineers. Each revolution of the rachet moves the spindle face 0.5mm towards the anvil face. The object to be measured is placed between the anvil face and the spindle face. The rachet is turned clockwise until the object is ‘trapped’ between these two surfaces and the rachet makes a ‘clicking’ noise. This means that the rachet cannot be tightened any more and the measurement can be read.

Type

The topmost image shows the three most common types of micrometer; the names are based on their application:
• Outside micrometer (aka micrometer caliper), typically used to measure wires, spheres, shafts and blocks.
• Inside micrometer, used to measure the diameter of holes.
• Depth micrometer, measures depths of slots and steps
(Source : www.technologystudent.com, darsg.wordpress.com, toolmonger.com and bjcande.com)
 
.Anytime Tools Professional Machinist Inspection Tool Set: DIAL CALIPER / MICROMETER / Stainless Steel Ruler