Starrett 12272 Electronic Outside Micrometer 5 Inch

Product Description

The STARRETT 12272 is an electronic outside micrometer designed for high-precision linear measurement in machining, manufacturing, and metrology applications. It delivers a resolution of 0.0001 inches and an accuracy of 0.000150 inches, making it suitable for tight-tolerance inspection work. The measuring faces are micro-lapped carbide, providing hardness and wear resistance for repeated contact with ferrous and non-ferrous workpieces. A friction thimble ensures consistent measuring force across readings. The tool features a black wrinkle and satin chrome finish with a ring-style lock nut and runs on a single included CR2450 battery.

This micrometer covers a measurement range up to 5 inches (101 mm maximum) with a throat depth of 3.16 inches (80.35 mm), accommodating larger workpiece cross-sections common in heavy machining environments. It is used by machinists, quality control technicians, and tool-and-die professionals in job shops, production floors, and inspection labs. The electronic readout eliminates interpolation error and speeds up repetitive measurement cycles. It is not intended for field or jobsite use where contamination or impact risk is high.

Key Features

• Resolution of 0.0001 inches for fine dimensional inspection
• Accuracy of 0.000150 inches across the full measurement range
• Micro-lapped carbide measuring faces resist wear and maintain flatness
• Friction thimble provides repeatable measuring force
• Ring-style lock nut secures the spindle position during reading transfer
• Includes CR2450 3V battery; no separate purchase required

Compatibility

Designed as a standard outside micrometer for workpieces requiring measurement up to 5 inches (101 mm), compatible with typical bench and fixture setups used in precision machining and inspection workflows.

Installation Notes

Calibration should be verified against a known standard before first use and after any impact or storage. Store the micrometer with the measuring faces slightly apart to prevent thermal contact stress. Battery replacement requires a CR2450 cell; power down the unit before swapping. Handle measuring faces with care — carbide is hard but can chip if dropped on a hard surface.