Starrett 50979 Micrometer Calibration Standard 6 Inch

Product Description

The STARRETT 50979 is a spherical end micrometer calibration standard engineered for high-precision measurement verification. Built to an accuracy of 0.0001 inch, it provides a reliable reference for checking and calibrating outside micrometers in shop, lab, or field environments. At 6 inches in length, it covers a common calibration range used across general machining, metrology, and quality control applications. The included heat insulating handle prevents thermal expansion errors caused by hand contact, preserving measurement integrity during use. Calibrated at the factory, the 50979 is ready for immediate use by metrology technicians, machinists, and quality inspectors working to close tolerances.

This calibration standard is suited for tool rooms, production floors, and calibration labs where outside micrometers must be periodically verified against a known reference. It is a practical choice for facilities operating under ISO, ANSI, or internal quality standards that require documented micrometer calibration. The spherical contact ends ensure consistent point contact against the micrometer anvil and spindle, reducing the effect of alignment variation during the calibration check.

Key Features

• Accuracy up to 0.0001 inch for high-precision micrometer verification
• 6-inch length covers a standard outside micrometer calibration range
• Spherical ends ensure consistent, repeatable contact geometry
• Factory calibrated and ready for immediate use
• Includes heat insulating handle to eliminate thermal expansion error from hand contact

Compatibility

Designed for use with outside micrometers requiring a 6-inch calibration reference standard. Suitable for standard micrometer calibration procedures in tool rooms, metrology labs, and production quality environments.

Installation Notes

Always hold the standard by the heat insulating handle, not the gauge body, to avoid thermal error from body heat. Before use, allow the standard and micrometer to reach the same ambient temperature, typically in a temperature-controlled environment. Clean both the micrometer anvil faces and the spherical ends of the standard with a lint-free cloth before each calibration check. Store the standard in its case when not in use to protect the calibrated surfaces.