Mitutoyo 123-128 Disc Micrometer 3 to 4 Inch

Product Description

The MITUTOYO 123-128 is a mechanical disc micrometer designed to measure workpieces in the 3 to 4 inch range where a standard flat anvil cannot reach recessed or narrow features. The 20mm disc anvil and spindle allow measurement of grooves, keyways, and disc-shaped workpieces that would be inaccessible to a conventional outside micrometer. Accuracy is rated at 0.0003 inch, with a 0.001 inch graduation and a resolution of 0.00005 inch. A ratchet stop thimble provides consistent measuring pressure for repeatable readings across multiple measurements or operators. The satin chrome finish reduces glare under shop lighting. Licensed HVAC, tool, and precision-measurement technicians install and use this instrument in production and field service environments.

The 123-128 is suited for dimensional inspection of disc-shaped components, thin flanges, grooves, and similar features on machined parts. Its 20mm disc diameter and 0.70mm disc edge thickness allow entry into tight clearances where a ball-end or flat anvil cannot seat properly. This micrometer is commonly used in machine shops, manufacturing lines, and maintenance settings where groove or disc-feature measurement is part of routine quality control or setup verification. One SR44 battery is included for the instrument indicator circuit.

Key Features

• 3 to 4 inch measuring range for mid-size disc and groove features
• 0.0003 inch accuracy with 0.001 inch graduation and 0.00005 inch resolution
• 20mm disc diameter and 0.70mm disc edge thickness for access to tight grooves
• Ratchet stop thimble ensures consistent, repeatable measuring force
• Steel anvil and spindle materials for durability under shop conditions
• Satin chrome finish reduces glare and surface reflectance
• TUV Certified to established dimensional measurement standards

Compatibility

Designed as an OEM-specification disc micrometer for measuring grooves, keyways, and disc-shaped part features in the 3 to 4 inch range. Suitable for use wherever a 20mm disc anvil profile is required for feature access.

Installation Notes

This instrument is handled and calibrated by qualified metrology technicians or precision machinists. Before use, clean contact surfaces and verify zero calibration against a known standard. Do not overtighten the thimble against a workpiece; use the ratchet stop to apply consistent measuring force. Store in the supplied case away from temperature extremes and moisture to maintain calibration integrity.