Starrett 63491 Mechanical Outside Micrometer 3 in Range

Product Description

The STARRETT 63491 is a mechanical outside micrometer with a 3-inch measurement range and a graduation of 0.0001 inches, delivering accuracy to 0.000050 inches. It features a ratchet stop thimble for consistent, repeatable measuring force and a ring-style lock nut to secure the spindle position once a measurement is taken. The measuring faces and anvil are made from solid carbide, providing exceptional wear resistance during frequent use. A digital counter is integrated for easy reading, and the one-piece spindle design is engineered for long-term dimensional stability. This tool is suited for precision measurement tasks in fabrication shops, machine shops, and field service environments.

The STARRETT 63491 is designed for trade professionals who require tight-tolerance outside measurements across a range of 0 to 3 inches. Typical applications include measuring shaft diameters, wall thicknesses, and machined component dimensions. It is appropriate for use in HVAC equipment manufacturing, plumbing component fabrication, electrical enclosure work, and general mechanical trades where dimensional accuracy is critical. The included lock nut and wrench allow secure adjustment and calibration in the field or shop.

Key Features

• Measurement range of 0 to 3 inches with 0.0001-inch graduation
• Accuracy to 0.000050 inches for tight-tolerance work
• Solid carbide measuring faces and anvil for extended wear life
• Ratchet stop thimble ensures consistent measuring force
• Integrated digital counter for fast, clear readings
• Extremely hard and stable one-piece spindle construction
• Ring-style lock nut included with wrench for field calibration

Compatibility

Designed as a general-purpose outside micrometer suitable for precision measurement tasks in mechanical, fabrication, and trade service applications.

Installation Notes

This instrument requires no installation but should be zeroed and verified against a calibration standard before use. Store the micrometer with the anvil and spindle faces slightly separated to prevent damage from thermal expansion. Clean measuring faces with a lint-free cloth before each use to ensure accurate readings. Calibration and maintenance should be performed by a qualified metrologist or per shop quality procedures.