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Various types of micrometres

Micrometres are precision measuring instruments used to measure dimensions with high accuracy’

Parts of micrometre
• Frame,
• Anvil,
• Locking device,

• Barrel,
• Spindle,
• Thimble,
• Ratchet stop

There are various types of micrometers available, each designed for specific measurement tasks and applications.
Here are some common types of micrometres.
1 Outside micrometre
• Description: Also known as a micrometre calliper, an outside micrometre is used to measure the external
dimensions of objects such as diameters, thicknesses, or lengths.
• Features: It consists of a C-shaped frame with a calibrated screw mechanism that moves a measuring
spindle perpendicular to the object being measured. The spindle has a flat anvil on one end and a measuring
face on the other.
• Applications: Outside micrometres are commonly used in machining, engineering, manufacturing, and
quality control for precise measurements of cylindrical or rectangular objects.
2 Inside micrometre
• Description: An inside micrometre is used to measure the internal dimensions of objects such as bores,
holes, or cylinders.
• Features: It consists of a C-shaped frame with a calibrated screw mechanism that moves a set of measuring
rods or anvils outward when turned. The rods have flat measuring faces on one end.
• Applications: Inside micrometres are commonly used in machining, automotive, and precision engineering
for measuring the diameter or internal dimensions of holes, cylinders, and other hollow objects.

3 Depth micrometre
• Description: A depth micrometre is used to measure the depth of holes, slots, or recesses.
• Features: It consists of a base, a calibrated rod or blade with a measuring face, and a thimble or dial gauge
for reading the measurement. The rod or blade is lowered into the hole or recess until it contacts the bottom
surface.
• Applications: Depth micrometres are commonly used in metalworking, woodworking, and machining for
measuring the depth of holes, counter bores, counter sinks, and other features.

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CITS : CG & M - Fitter - Lesson 10 CITS : CG & M - Fitter - Lesson 10