Fowler 52-225-006-1 Premium Depth Micrometer, 0-4 Measuring Range...

The Fowler Premium Depth Micrometers have a measurement range of 0 to 3" or 0 to 4", a base of 2.5" or 4", and a resolution (or smallest graduation interval) of 0.001", with + or – 0.0003" of accuracy. The vernier scale of microfine graduations on satin chrome finish provides precise, readable measurements. Depending on the range of the model, the gauges include either three or four 1" long/0.176" diameter measuring rods. The rods are interchangeable and are fitted to the gauge spindle against a positive stop and then locked for accuracy and stability. The bases are 2.5"long, and the rods and threads are ground, hardened, and lapped for durability and accuracy. They come with a spanner wrench and hardened case. The gauges conform to Federal Accuracy specifications. Depth gauges are typically used in manufacturing, machining, and mechanical engineering.

Depth gauges are precision measuring instruments used to determine the depth of any shape that has a step, groove, or slot. These gauges often take the form of sliders that travel on a measuring beam or rods, are moved to position by hand, and then adjusted with a calibrated screw. The base of the gauge rests at the top of the shape whose recession is to be measured, while the beam or rods extend to the bottom of the recession to determine the measurement. Gauge position is read from a graduated scale, dial, counters, or an electronic display.

The Fred V. Fowler Company manufactures inspection and measurement instruments such as electronic indicators, calipers, bore gages, and digital scales. The company, founded in 1946, is headquartered in Newton, MA.