What is a screw gauge?

Update:08 Jun 2020
Summary:

Screw Gauge is an instrument which is used for measurin […]

Screw Gauge is an instrument which is used for measuring accurately the diameter of a thin wire or the thickness of a sheet of a metal. Screw driver consists of a U-shaped frame fitted with a screwed spindle which is attached to a thimble. Parallel to the axis of the thimble, a scale graduated in mm is engraved.

Uses of Screw Gauge

1. It is used for finding the diameter of a steel rod which is used in the construction of a building.

2. Used for measurement of components of industry and their manufacturing.

3. As we know it is used for measure the gauge of a metal sheet or a wire, by this it is named as screw gauge

There are many types of gauges available to measure screws, nuts and bolts. Screws specifically can be measured with a number of different gauges. There are three measurements to identify a screw (excluding head and drive-style which you cannot measure but compare).

The first being Screw diameter. A screws diameter is typically measured by a hole that you insert a screw into. It should fit snugly in the hole and not wiggle around.

Then once you’ve measured the diameter of the screw you can identify the length of the screw. Most screws measure from directly under the head of the screw but flat head screws measure from the top of the head. A good screw gauge will account for this.

After you’ve determined the length the final aspect is the thread pitch. Thread pitch can be determined in two ways. In a good screw gauge, there will be threading cut into it where you can compare. The other option is to use a size run of nuts (that have their sizes marked) and find the one that fits the screw. The thread gauge of the nut and screw will be the same giving you your final result.

Screw Gauge or more often micrometer screw uses a screw to amplify a very small movement so that it can be easily read.
The first micrometric screw was invented by William Gascoigne in the 17th Century, as an enhancement of the Vernier
Least count of Screw Gauge is 0.001 cm
For full information about screw gauge like :-
Calculation of Least Count of Screw Gauge.
Diameter / Thickness Measurement of an object.
Errors in Screw Gauge ( Positive and Negative ).
How to remove Errors