What is Micrometer Screw Gauge?

Micrometer Screw Gauge

The word micrometer is refers to two different terminologies the first one is a smaller unit of metric measurement which is 1/1000 of millimeter and the second on is measuring instrument called micrometer which can measure dimensions up to higher precision and accuracy compare to vernier caliper because of in measuring process of a micrometer the line of object to be measured is always parallel to axis of instrument.

What is micrometer?

Is the instrument used t o measure smaller values of dimensions like lengths, widths and breadths of accurate machine parts and objects  up to accuracy of 0.01 mm in case of metric scale and 1/1000 of an inch if there is inches  scale is engraved on a micrometer screw gauge.

The micrometer screw was firstly invented by William Gascoigne England in the 17th century. This was used to measure angular distances between stars in telescopes. The first commercial version released in 1867.It has a many applications in every field of science and engineering and now days so many variety of micrometer is available for industrial use in different conditions like linear lengths, angular distances and bore depths e.t.c.

Least count of micrometer:

Its means that a minimum measurement that  an instrument can measure, in this case for metric models it is 0.01mm and 0.001 inch for  imperial scales.

Working principle:

Micrometer comprises of a thread based mechanism in which a thread of a specific pitch, provided on a moving part that’s called spindle and it rotates in a fixed nut and that thread of precision-ground with a particular pitch on spindle makes it advancement countable for every one rotation up to 1/50th of one rotation of spindle and that’s how micrometer works. In simple words the distance covered by spindle is known because of its thread pitch is known so one rotation or one turn of spindle travels it towards or opposite to the object to a particular distance.

From above explanation now you can easily understand reading and the working principle of micrometer as the pitch of precision-ground thread is 0.5 mm for metric scale its means in one turn of spindle travels it 0.5 mm and   1/50th of one turn means 0.01 mm travel of spindle and to identify how many parts out of 50 parts of a one spindle rotation there is a sleeve provided on spindle and thimble which has a scale engraved around its perimeter as shown in picture.

micrometer parts

Ranges Available:

Zero to 25 mm, 25 to 50 mm and 50 to 75 mm e.t.c




Check Also

Vernier Caliper Classification

Vernier Caliper Classification and Types Vernier Caliper is used to measure wide variety of lateral …