Spi 21-997-2 Test Indicator Ball Contact Point

Product Description

The SPI 21-997-2 is a ball-style contact point designed for use with dial test indicators in precision measurement applications. The contact tip is a 1.00 mm (0.039 inches) diameter stainless steel ball, and the overall contact point length is 16.80 mm (0.61 inches). Stainless steel construction provides corrosion resistance and long service life under repeated use. This replacement contact point is installed by machinists, metrologists, and quality control technicians who require accurate, repeatable surface contact when inspecting parts on machine tools, surface plates, or CMM fixtures.

This contact point is suited for precision measurement environments including machine shops, tool rooms, and quality inspection departments. It threads onto compatible dial test indicator spindles and is used when measuring small bores, grooves, or contoured surfaces where a standard flat contact cannot maintain consistent contact. Its compact ball tip allows access to tight geometry that larger contacts cannot reach.

Key Features

• Ball-style tip for consistent contact on curved and contoured surfaces
• 1.00 mm (0.039 inches) ball diameter for access to tight or small-radius geometry
• 16.80 mm (0.61 inches) contact point length
• Stainless steel construction for corrosion resistance and durability
• Drop-in replacement style for quick field swap

Compatibility

Designed for use with the SPI Integral Series dial test indicators.

Installation Notes

Installation is performed by machinists or quality technicians and requires no special tooling beyond what is standard for indicator maintenance. Remove the existing contact point by unscrewing it from the indicator spindle thread before installing the replacement. Ensure the indicator is not under load or mounted in a fixture under tension during the swap. Verify seating is snug but do not overtighten, as excess force can damage the spindle thread on precision instruments.