Spi 31-479-9 Inside Outside Diameter Caliper Attachment

Product Description

The SPI 31-479-9 is a two-piece inside and outside diameter attachment designed to expand the measurement capability of standard 6-inch dial or electronic calipers. The attachment mounts to the caliper jaw area and enables thread pitch measurement across a range of 1.00 to 1.50mm pitch, covering common metric fastener and fitting threads. The chrome finish resists corrosion and wear in shop environments. Instructions are included. This accessory is used by machinists, pipe fitters, and maintenance technicians who need accurate thread measurement without investing in a dedicated thread micrometer.

This attachment is suited for use in machine shops, maintenance facilities, and field service environments where metric thread identification is a routine task. It fits standard 6-inch dial calipers and 6-inch electronic digital calipers. Technicians working with metric-threaded fittings, fasteners, or components in HVAC, plumbing, or industrial equipment will find this a practical add-on to existing caliper tooling. The two-piece set covers both inside and outside diameter thread measurement in a single kit.

Key Features

• Measures inside and outside diameter thread profiles with a standard 6-inch caliper
• Compatible with 1.00 to 1.50mm pitch threads
• Two-piece set covers both ID and OD measurement in one kit
• Chrome finish for corrosion resistance in shop conditions
• Instructions included for straightforward setup
• Lightweight at 0.05 pounds for easy handling and storage

Compatibility

Designed for use with 6-inch dial or electronic calipers as stated by the manufacturer. Specific caliper model compatibility beyond this size and type is not provided in the product data.

Installation Notes

Attachment and removal should be performed with the caliper jaws fully closed and the caliper powered off or the dial at rest. Follow the included instructions for correct jaw mounting and positioning before taking measurements. Handle the chrome-finished contact surfaces carefully to avoid nicks or burrs that could affect measurement accuracy.