Spi 21-377-7 Horizontal Dial Test Indicator 0.0005 in

Product Description

The SPI 21-377-7 is a horizontal dial test indicator designed for precision measurement in machining, inspection, and quality control applications. It covers a range of 0 to 0.02 inches with a graduation of 0.0005 inches and a matching accuracy of 0.0005 inches, making it appropriate for close-tolerance work. The 1.25-inch white dial reads 0-10-0, allowing the technician to read deflection in both directions from center. Movement is fully jeweled for durability and smooth operation, and the body carries a satin chrome finish. A NIST traceability certificate is included, supporting use in documented inspection environments.

This indicator suits horizontal gauging setups where a standard plunger-style indicator cannot reach or would interfere with adjacent surfaces. It is commonly used on surface plates, height gages, and CMM fixtures in tool rooms, job shops, and production inspection departments. The dovetail mount accepts standard dovetail extensions, giving the technician flexibility in reach and positioning. The universal clamp and included accessories allow quick setup across a range of fixturing arrangements.

Key Features

• 0 to 0.02 inch measurement range with 0-10-0 bidirectional dial reading
• 0.0005 inch graduation and 0.0005 inch accuracy for close-tolerance inspection
• Fully jeweled movement for consistent feel and long service life
• Dovetail mount with included 5/32 inch and 3/8 inch dovetail extensions
• 1.25-inch white dial with satin chrome finish for clear readability
• NIST traceability certificate included for documented quality control use
• Kit includes two contact points, height gage bar, universal clamp, and fitted case

Compatibility

Designed for use with standard dovetail-style indicator holders, arms, and fixtures. The included 5/32 inch and 3/8 inch dovetail extensions allow mounting to most common surface gage arms, height gages, and inspection fixtures that accept dovetail-style horizontal indicators.

Installation Notes

Horizontal dial test indicators are installed by metrologists, machinists, and quality control technicians using standard indicator holders or magnetic base arms. Secure the dovetail shank firmly before taking measurements to prevent movement errors. Handle the contact point and jeweled movement with care — avoid side-loading or dropping the indicator, as impact can damage the movement. Zero the dial against a known reference surface before use.