The basic difference between screw gauge and vernier caliper is that screw gauge is used to measure only external measurement while vernier caliper is used to measure external as well as internal measurement. The least count of vernier caliper is 0.01mm while the least count of screw gauge is 0.001 mm.
Micrometer Screw gauge and vernier caliper both are length measuring devices.
Difference between screw gauge and vernier caliper in tabular form
|Micrometer Screw gauge||Vernier caliper|
|It has a screw to measure so that it is called a Screw gauge.||It is invented by Perri vernier and has calipers to kept so that it is called Vernier caliper.|
|It has a circular scale.||It has a vernier scale.|
|It rotates to measure the objects.||It slides to measure the length.|
|It measures the thickness and diameter of a very small object just externally.||It measures the thickness, depth, external and internal diameter of the object.|
|Its usual least count is 0.001 cm.||Its usual least count is 0.01 cm.|