The smooth type micrometer, also known as the standard type micrometer, is used to measure the flatness and parallelism of precision workpieces.

Smooth-type micrometer calipers are categorized by base size specifications into 150 types.x150，200x150，200x200，200x300，300x300。

The smooth micrometer base has a 0th grade precision with a flatness of up to 6 micrometers. It can also be customized to 00th or 000th grade as per customer requirements. The 00th grade base features a flatness of 3 micrometers, while the 000th grade base has a surface roughness of 1.5 micrometers.

The smooth precision micrometer can be equipped with a torsion spring gauge, lever gauge, or standard micrometer and percentage gauge for readings according to the user's actual needs. This instrument includes only the base and auxiliary measuring rod; various indicating gauges must be purchased separately by the user.

The smooth measuring rod of the micrometer gauge has a total height of 260mm, with a large measurement height of 200mm, and the distance E from the indicator axis to the measuring rod is 85mm.