Spi 12-391-9 Electronic Outside Micrometer 2.5 in

Product Description

The SPI 12-391-9 is an electronic outside micrometer designed for precise external dimensional measurement in machining, tooling, and quality control environments. It features a solid carbide measuring face for wear resistance and a fast sliding thimble that speeds up measurement compared to a standard rotating thimble. Resolution is 0.0005 inches and accuracy is 0.001 inches, making it suitable for close-tolerance inspection work. The 3-inch throat depth allows measurement of deep or recessed workpiece features that a standard micrometer cannot reach. Machinists, quality technicians, and tool and die professionals are the primary users of this instrument.

The SPI 12-391-9 is well-suited for inspection tasks on deep-throated workpieces in job shops, manufacturing facilities, and metrology labs. The extended 3-inch throat depth makes it particularly useful when measuring stock or features set back from an edge. The sliding thimble design reduces the time required to traverse the full measurement range, which benefits high-volume inspection workflows. Includes a protective carrying case for storage and transport.

Key Features

• Solid carbide measuring face resists wear under repeated use
• Fast sliding thimble for rapid spindle travel across the measurement range
• 0.0005-inch resolution for fine-tolerance dimensional checks
• 3-inch throat depth enables measurement of deep or recessed features
• Electronic readout eliminates thimble-line interpolation errors
• Includes protective carrying case

Compatibility

Designed as a general-purpose electronic outside micrometer for external measurement applications up to 2.5 inches, compatible with standard metrology workflows requiring deep-throat access.

Installation Notes

This instrument requires no installation. Calibrate or zero the micrometer before use according to the manufacturer procedure using a calibrated standard. Store in the included case when not in use to protect the measuring faces and electronic components. Battery replacement should be performed with the spindle in a stable position to avoid damage to the electronic assembly.