Spi 21-052-6 Ball Contact Point Steel Interapid

Product Description

The SPI 21-052-6 is a ball-style contact point designed for use with dial test indicators. It attaches to the indicator spindle and provides a hardened steel ball tip for accurate surface contact during measurement work. The ball diameter is 0.078 inches (2.00 mm), and the overall contact point length is 0.812 inches. The steel construction delivers consistent wear resistance in repetitive gauging applications. This replacement contact point is typically installed by machinists, metrologists, toolroom technicians, and quality-control personnel working with precision measurement instruments.

This contact point is suited for bench measurement, fixture gauging, and machine tool inspection setups where a ball-tip stylus is preferred over a flat or pointed contact. It threads directly onto compatible test indicator spindles and is appropriate for both surface plate work and in-process inspection on manual or CNC machine tools. The compact ball tip allows contact on small bores, grooves, and contoured surfaces where larger tips would not seat properly.

Key Features

• Ball diameter of 0.078 inches (2.00 mm) for contact on small-radius and contoured features
• Overall contact point length of 0.812 inches for standard reach applications
• Steel construction for wear resistance in repetitive gauging cycles
• Replacement-style fit for Interapid test indicators
• Sold individually, one contact point per package

Compatibility

Designed for use with Interapid test indicators as stated by the manufacturer. Verify thread size and spindle configuration on the specific indicator model before installation.

Installation Notes

Contact point replacement is performed by hand or with a small open-end wrench, depending on the indicator design. Remove the indicator from service before changing the contact point to prevent stylus deflection from damaging the movement. Avoid overtightening, as excessive torque can distort the spindle threads on precision indicators. Confirm the contact point is fully seated and the indicator reads zero correctly before returning the instrument to service.