Starrett 50978 Micrometer Calibration Standard 125mm

Product Description

The STARRETT 50978 is a spherical end micrometer calibration standard designed to verify and maintain the accuracy of outside micrometers. Measuring 125mm in length, this calibration standard features spherical contact ends that provide consistent, repeatable point contact during calibration checks. It includes a heat insulating handle, which prevents thermal expansion errors caused by hand warmth during use. Dimensional accuracy is critical in precision measurement environments, and this standard is suited for use by machinists, quality control technicians, metrologists, and tool calibration specialists working in machine shops, manufacturing facilities, and metrology labs.

This calibration standard is used to set and verify outside micrometers in the 125mm range. It is appropriate for both shop-floor spot checks and formal calibration procedures. The heat insulating handle allows the technician to hold the standard without transferring body heat to the measuring surface, preserving dimensional integrity during the verification process. It is a practical reference tool for any environment where micrometer accuracy is routinely audited.

Key Features

• 125mm nominal length for calibrating micrometers in that measurement range
• Spherical contact ends provide consistent point contact for repeatable readings
• Includes heat insulating handle to minimize thermal expansion errors during handling
• Compact and lightweight at 0.5 pounds for easy bench or toolbox storage
• Sold individually for single-standard calibration setups

Compatibility

Designed for use with outside micrometers requiring a 125mm calibration reference standard. No specific compatible model numbers were provided in the product data.

Installation Notes

Calibration standards of this type are handled by metrology technicians or quality assurance personnel, not installed in the traditional sense. Always allow the standard to thermally stabilize in the measurement environment before use. Hold the standard exclusively by the heat insulating handle to avoid transferring body heat to the measuring surfaces. Store in a protective case away from temperature extremes and physical shock to preserve dimensional accuracy.