Starrett 50985 Micrometer Calibration Standard 9 in

Product Description

The STARRETT 50985 is a spherical end micrometer calibration standard designed for verifying and calibrating outside micrometers used in precision measurement applications. At 9 inches in length, it provides a reference gauge with accuracy up to 0.00015 inches, making it suitable for high-tolerance inspection work in machine shops, tool rooms, and metrology labs. The standard comes with a heat insulating handle to prevent thermal expansion from hand contact, which helps maintain measurement integrity during use. It is a calibrated reference artifact intended for professional use by machinists, calibration technicians, and quality control personnel.

This calibration standard is used wherever outside micrometer accuracy needs to be verified or documented. Typical applications include in-shop calibration routines, periodic instrument verification, and quality management system requirements. The 9-inch length accommodates larger-range micrometers commonly used in manufacturing and fabrication environments. The included heat insulating handle is especially useful during extended calibration sessions where repeated handling could otherwise introduce thermal error into readings.

Key Features

• 9-inch maximum length for use with larger-range outside micrometers
• Accuracy to 0.00015 inches for high-tolerance calibration work
• Factory calibrated — ready for use as a reference standard
• Includes heat insulating handle to minimize thermal growth from hand contact
• Spherical ends provide consistent contact geometry with micrometer anvil and spindle

Compatibility

Designed as an OEM-style calibration reference for use with outside micrometers requiring a 9-inch range standard. Suitable for any outside micrometer with matching anvil contact geometry.

Installation Notes

Calibration standards should be handled by the insulating handle only to avoid introducing thermal error from body heat. Store the standard in its case when not in use and allow it to reach ambient temperature before taking reference measurements. This type of artifact is typically used by calibration technicians following documented procedures in accordance with applicable metrology standards such as ANSI/NCSL Z540 or ISO 17025 requirements.