Starrett 67858 Mechanical Micrometer 10 in Ratchet Stop

Product Description

The STARRETT 67858 is a mechanical outside micrometer designed for high-precision measurement in demanding shop and field environments. It covers a full 10-inch measurement range with a graduation of 0.0003 inches and a stated accuracy of 0.0003 inches, making it suitable for applications where tight dimensional tolerances are required. The ratchet stop thimble delivers consistent, repeatable measuring pressure, and the solid carbide measuring faces resist wear over extended service life. This instrument is used by machinists, metrologists, and quality-control technicians working with large-diameter workpieces.

The 67858 is intended for use in precision machining, manufacturing, and inspection environments where large-range outside diameter measurement is required. With a maximum measurement of 10 inches and a gage depth of 4.625 inches, it handles oversized shafts, bores, and components that standard bench micrometers cannot reach. The instrument includes an extension rod with a maximum length of 6 inches, extending its versatility in deep-reach applications. It ships with a case, contacts, a 9-inch setting ring, wrenches, and instructions, giving technicians everything needed for initial setup and calibration verification.

Key Features

• 10-inch measurement range with 0.0003-inch graduation for high-resolution readings
• Stated accuracy of 0.0003 inches for reliable dimensional verification
• Ratchet stop thimble ensures consistent measuring pressure and repeatable results
• Solid carbide measuring faces for extended wear resistance in production environments
• 3-contact-point design with a maximum extension rod length of 6 inches for deep-reach measurement
• Includes case, contacts, 9-inch setting ring, wrenches, and instructions for complete out-of-box readiness

Compatibility

Designed as a large-range outside micrometer for use with workpieces up to 10 inches in outside diameter; intended for professional metrology and precision machining applications.

Installation Notes

Calibration and verification should be performed by a qualified metrologist or machinist using the included setting ring before placing the instrument into service. Store the micrometer in the provided case when not in use to protect the carbide measuring faces and maintain calibration integrity. Do not overtighten the thimble or apply force beyond the ratchet stop engagement, as this can introduce measurement error or damage the spindle thread.