Starrett 50993 Micrometer Calibration Standard 13 in

Product Description

The STARRETT 50993 is a spherical end micrometer calibration standard designed to verify and maintain the accuracy of outside micrometers used in precision measurement applications. At 13 inches in length, it accommodates the calibration of large-range micrometers with an accuracy of up to 0.00017 inches. The standard is factory calibrated and ships with a heat insulating handle, which prevents thermal expansion errors caused by hand contact during use. Dimensional calibration tools like this are relied upon by quality technicians, machinists, and metrologists to ensure measuring equipment stays within tolerance.

This calibration standard is suited for use in machine shops, manufacturing facilities, toolrooms, and quality control labs where micrometer accuracy must be periodically verified. The 13-inch length makes it appropriate for calibrating micrometers with extended measurement ranges. The included heat insulating handle is a practical feature for bench use, reducing the risk of measurement error introduced by body heat transfer to the reference bar during the calibration process.

Key Features

• Spherical end design for consistent, repeatable contact point engagement
• 13-inch length supports calibration of large-range outside micrometers
• Accuracy up to 0.00017 inches for high-precision verification work
• Factory calibrated — ready for immediate use as a reference standard
• Includes heat insulating handle to minimize thermal expansion errors during handling

Compatibility

Designed for use with outside micrometers requiring a 13-inch calibration reference standard. Consult the micrometer manufacturer specifications to confirm range compatibility before use.

Installation Notes

Calibration standards are handled and used by quality technicians or tool room personnel — not installed in a system. Store the standard in its case when not in use to protect the reference surfaces. Always allow the standard and the micrometer being checked to reach the same ambient temperature before taking reference measurements, and use the heat insulating handle during all checks to prevent thermal growth on the bar.