Use Fowler No. 52-246 Blade Micrometers to measure the outside diameter of workpieces which have narrow grooves, "T" slots and other dimensions blocked by shoulders or lands where standard type micrometers cannot be applied. • Hammertone blue baked enamel frame • Microfine graduations on satin chrome finish for easy reading. • Anvil & spindle hardened & precision ground with microlap finish on ends. Spindle thread is hardened, ground and lapped. • Non-rotating spindle • Ratchet thimble • Wrench included for quick and easy zero adjustment on sleeve • Sizes over 1" include a standard • Includes case