Spi 31-481-5 Inside Outside Diameter Caliper Attachment

Product Description

The SPI 31-481-5 is a two-piece inside and outside diameter attachment set designed to extend the measuring capability of standard 6-inch dial or electronic calipers. The attachment mounts to the caliper jaw and enables measurement of internal and external diameters on threaded features, grooves, and bores that standard jaws cannot reach directly. Chrome finish provides corrosion resistance and durability under shop conditions. Compatible pitch range spans 1.5 to 2.5mm, covering a broad range of metric thread and bore measurement tasks. Instructions are included in the package.

This attachment set is suited for machine shops, tool rooms, and maintenance environments where technicians need to measure internal or external diameters beyond the reach of standard caliper jaws. It pairs with 6-inch dial calipers or 6-inch electronic digital calipers. The two-piece construction allows both inside and outside diameter measurement without swapping tools, making it practical for inspection and quality control work on threaded fasteners, bores, and cylindrical features.

Key Features

• Measures both inside and outside diameters with a single attachment set
• Compatible with 6-inch dial and 6-inch electronic calipers
• Pitch range: 1.5 to 2.5mm
• Chrome finish for corrosion resistance in shop environments
• Includes printed instructions for setup and use
• Compact two-piece kit weighing 0.05 pounds

Compatibility

Designed for use with 6-inch dial or electronic calipers as stated by the manufacturer.

Installation Notes

Installation of this attachment is performed by machinists or metrology technicians and requires no special tools beyond the caliper itself. Follow the included instructions for proper jaw alignment and attachment seating before taking measurements. Verify the caliper is zeroed after attaching the accessory and before recording readings. Do not force the attachment onto caliper jaws — confirm jaw style compatibility before use.