INSIZE Blade Micrometer The anvil and the spindle have a blade for measuring the groove diameter of shafts, keyways, and other hard-to-reach portions. Specifications include... 0-1" Measuring Range 0.0001" Graduations .00016" Accuracy Features include... Ratchet Stop for constant force Supplied in fitted case Blade Dimensions... 0.030" Wide 0.236" Tall 0.256" Long