Spi 12-405-7 Inside Dial Caliper Gage 1-7/8 to 2-7/8 in

Product Description

The SPI 12-405-7 is an inside dial caliper gage designed to measure internal diameters and bores with a measurement range of 1-7/8 to 2-7/8 inches. The gage reads in 0.001-inch graduations and carries an accuracy rating of 0.0015 inches, making it suitable for precision inspection work in machine shops, manufacturing facilities, and maintenance environments. Ball contact points are standard and allow consistent seating against the bore wall. The 3-1/4-inch leg length provides reach into recessed features. Machinists, quality technicians, and tool-and-die professionals are the primary users of this instrument.

This inside dial caliper gage is used for verifying internal dimensions on machined bores, pipe fittings, bushings, and similar components where tight tolerances must be confirmed. It is appropriate for both production inspection and incoming quality checks. The ball contact point design reduces measurement error caused by tip geometry when working with curved internal surfaces. The aluminum alloy, copper alloy, and steel construction keeps the instrument rigid while managing overall weight.

Key Features

• Measurement range of 1-7/8 to 2-7/8 inches covers common bore and fitting sizes
• 0.001-inch graduation for fine resolution on precision inspection tasks
• Accuracy of 0.0015 inches for reliable, repeatable readings
• Ball contact points included for consistent contact on curved internal surfaces
• 3-1/4-inch leg length provides reach into deeper or recessed bore features
• Multi-material construction (aluminum alloy, copper alloy, steel) balances rigidity and weight

Compatibility

Designed as a precision hand measurement instrument for use with internal diameters and bores falling within the 1-7/8 to 2-7/8-inch range. No specific machine or system compatibility is stated by the manufacturer for this gage.

Installation Notes

This instrument is a hand-held precision measurement tool and does not require permanent installation. Before use, zero the dial indicator per standard gage calibration procedures and inspect contact points for wear or damage. Store the gage in its case away from temperature extremes and contaminants to maintain calibration integrity. Handle with care to avoid dropping, which can shift calibration or damage the dial mechanism.