Spi 21-051-8 Ball Contact Point Interapid Test Indicators

Product Description

The SPI 21-051-8 is a ball-style contact point designed for use with dial test indicators requiring precision measurement tips. The contact tip features a 1.50 mm (0.059 inches) ball diameter machined from steel, providing a consistent and durable contact surface for surface runout, bore alignment, and part deflection measurements. The overall contact point length is 0.812 inches. This type of replacement tip is standard equipment for metrology professionals and machine shop technicians who rely on Interapid-style indicators for close-tolerance work.

This contact point is suited for use in machine shops, quality control labs, and toolroom environments where precise indicator readings are required. It threads into compatible dial test indicator bodies as a direct replacement tip. Typical applications include checking runout on rotating assemblies, verifying surface flatness, and setting up workpieces on milling machines, lathes, and surface plates.

Key Features

• Ball diameter: 1.50 mm (0.059 inches) for precise point contact measurement
• Contact point length: 0.812 inches for standard indicator reach
• Steel construction for wear resistance and dimensional stability
• Designed for use with Interapid test indicators
• Lightweight at 0.1 pounds for minimal indicator loading

Compatibility

Designed for use with Interapid test indicators as a replacement ball contact point tip.

Installation Notes

Installation is performed by machinists or metrologists and requires no specialized tools beyond what is standard for indicator tip changes. Thread the contact point carefully into the indicator spindle to avoid cross-threading or damaging the precision threads. Ensure the indicator is removed from the measuring setup before changing tips. Verify tip seating and indicator zero before returning to service.