Spi 20-976-7 Ball Needle Contact Point Dial Indicator

Product Description

The SPI 20-976-7 is a ball needle contact point designed for use with dial indicators in precision measurement applications. It features a chrome alloy steel ball tip measuring 0.125 inches in diameter, attached to a contact point shaft with a total length of 0.75 inches. The threaded end uses a 4-48 thread standard, conforming to AGD Group 1 industry designation. Machinists, tool-and-die technicians, and quality control inspectors use this contact point when measuring surfaces that require a small, well-defined contact area. The ball needle style is well suited for detecting surface variations in bores, slots, and contoured workpieces.

This contact point is intended for installation on dial indicators in manufacturing, machine shop, and inspection environments. It is appropriate for both bench-top and in-machine measurement setups where AGD Group 1 accessories are specified. Applications include surface runout checks, bore alignment, and feature-to-feature measurement where a small ball contact minimizes deflection error and improves repeatability on curved or angled surfaces.

Key Features

• Ball needle tip style for precise contact on curved and contoured surfaces
• Chrome alloy steel construction for wear resistance and dimensional stability
• 0.125 inch ball diameter for small-contact, high-accuracy measurement
• 0.75 inch contact point length for standard reach applications
• 4-48 thread fits AGD Group 1 dial indicators
• Lightweight at 0.1 pounds, minimizing added mass on sensitive indicator stems

Compatibility

Designed for use with dial indicators accepting 4-48 threaded contact points meeting AGD Group 1 specifications.

Installation Notes

Installation is performed by threading the contact point into the indicator stem by hand until snug. Use the appropriate small wrench or contact point tool if the indicator manufacturer specifies a torque method, but avoid over-tightening, which can damage the 4-48 thread. Remove the existing contact point before installation and verify the replacement thread specification matches the indicator stem. Handle chrome alloy steel contact points carefully to avoid nicking the ball tip, which would introduce measurement error.