Spi CMS160725044 Hole Micrometer 0.65-0.80 Inch Nist

Product Description

The SPI CMS160725044 is a mechanical hole micrometer designed to measure internal bore diameters from 0.6500 to 0.8000 inches with high precision. It delivers an accuracy of 0.0001 inches and a graduation of 0.0002 inches, making it a dependable instrument for close-tolerance work in machine shops, maintenance facilities, and precision manufacturing environments. The micrometer features three self-centering contact points with carbide measuring surfaces and a ratchet stop thimble for consistent, repeatable gauging force. A NIST traceability certification is included, satisfying most quality management and documentation requirements. Machinists, toolmakers, and metrology technicians are the primary users of this instrument.

This hole micrometer is suited for internal diameter measurement in applications where bore accuracy is critical, including engine rebuilding, hydraulic component inspection, and precision machining. The 0.6500 to 0.8000 inch measurement range covers a common bore size class found in both production and maintenance settings. A gage depth of 3.1500 inches allows measurement in moderately deep bores, and the included extension rod extends reach up to 6.0000 inches maximum. The chrome finish resists corrosion during shop use. A setting ring of 0.6500 inch diameter is included for on-site calibration checks.

Key Features

• Measurement range: 0.6500 to 0.8000 inches with 0.0002-inch graduation
• Accuracy of 0.0001 inches for close-tolerance bore inspection
• Three self-centering contact points ensure consistent alignment in the bore
• Carbide measuring surfaces for extended wear resistance
• Ratchet stop thimble provides repeatable measuring force
• NIST traceability certification included for quality system compliance
• Includes one setting ring and one extension rod

Compatibility

Designed as a standalone precision measuring instrument for internal bore diameters in the 0.6500 to 0.8000 inch range. Compatible with standard calibration procedures using the included 0.6500-inch setting ring.

Installation Notes

Hole micrometers are used by machinists and metrology technicians and require no installation in the traditional sense. Before use, verify calibration against the included setting ring and allow the instrument to thermally stabilize to the ambient shop temperature. Handle carbide contact surfaces with care to avoid impact damage. Store the micrometer in its case when not in use to protect the measuring surfaces and maintain calibration integrity.