Dial Indicator Depth Gauge

Mitutoyo 7221A - Depth Gauge with Dial Indicator, 150 mm Base Plate

The Mitutoyo 7221A is a mechanical depth gauge based on a dial indicator for accurate depth measurements in machine shops, production, and quality control. It uses a rectangular base plate 150 mm long with a hardened, precision ground, and micro-lapped reference surface. This ensures measurements are taken from a flat and reliable reference surface, improving repeatability when measuring depths of grooves, drill holes, and steps.

With a measuring range of 0–200 mm and a dial division accuracy of 0.01 mm, an overall accuracy of ±15 µm, a dial stroke length of 10 mm, and a base plate flatness of 5 µm, the measuring instrument is well suited for demanding machining and assembly measurements. The depth gauge is equipped with a spherical contact tip with a radius of 1.5 mm and a carbide tip. The ball tip performs well in both drilled holes and narrow grooves, and the carbide is resistant to wear and tear even after long-term use.

An extension rod set is included, with five extension rods in different lengths (10, 20, 30, 30, and 100 mm). These allow the measuring depth range to be adapted to a wide range of applications without the need to change the measuring instrument. The depth gauge is supplied in a box together with a spindle lift lever, a carbide ball tip, and a Mitutoyo 2902AB dial indicator. The construction is mechanically sturdy yet easy to handle in use, making the 7221A a reliable choice for professionals requiring both accuracy and quick repeatability in depth measurements.