Spi 21-389-2 Dial Test Indicator 0.8mm Vertical Dovetail

Product Description

The SPI 21-389-2 is a vertical-style dial test indicator designed for precision measurement in machine shop, toolroom, and quality-control environments. It delivers a maximum measurement range of 0.8 mm per revolution with a 0-40-0 bidirectional dial reading and an accuracy of 0.013 mm. The fully jeweled movement reduces friction for consistent, repeatable results across extended use cycles. A satin chrome finish resists corrosion and wear. The 32 mm white dial provides high contrast for easy reading in shop conditions. This indicator is calibrated to NIST-traceable standards and ships with a short-form certificate of calibration, making it ready for use in documented quality systems.

This dial test indicator is suited for surface plate work, machine tool setup, runout checks, and fixture alignment in both production and inspection settings. The dovetail mount accepts standard dovetail extensions, allowing it to fit most dial indicator holders and magnetic base arms. The universal clamp and height gage bar included in the kit expand setup flexibility. Machinists, toolmakers, metrologists, and quality technicians are the primary users. The two included contact points cover a range of common probing applications without additional purchases.

Key Features

• Fully jeweled movement for low-friction, repeatable readings
• NIST-traceable calibration with short-form certificate of calibration included
• Dovetail mount with included 5/32 inch and 3/8 inch dovetail extensions for broad holder compatibility
• 32 mm white dial with 0-40-0 bidirectional graduation at 0.01 mm increments
• Satin chrome finish for durability in machine shop environments
• Kit includes universal clamp, height gage bar, fitted case, and two contact points

Compatibility

Designed for use with standard dovetail-style indicator holders and magnetic base arms that accept dovetail shanks. Included 5/32 inch and 3/8 inch dovetail extensions expand mounting options across common indicator stands and fixtures.

Installation Notes

Mount the indicator in a rigid dovetail holder before zeroing to avoid measurement error from flex in the setup. Verify the contact point is aligned with the measurement axis and that stylus travel is within the 0.8 mm range before taking readings. Handle the jeweled movement with care and avoid dropping the instrument, as impact can damage the bearing train. Calibration verification should follow your facility quality procedures prior to use in documented inspection work.