Starrett No. 436 Mechanical Outside Micrometer with Ratchet Thimble measures external dimensions from 18 to 19 inches with 0.001" graduation. The ratchet thimble provides consistent measuring pressure for repeatable readings on large-diameter parts. This outside micrometer is well suited for metalworking and fabrication tasks that require accurate large-dimension checks in the 18–19 inch range.
