Spi 20-337-2 Cupped Ball Contact Point 3mm Dial Indicator

Product Description

The SPI 20-337-2 is a cupped ball contact point designed for use with dial indicators in precision measurement applications. Machined from solid carbide, the contact tip measures 3 mm in diameter and features a 4-48 threaded shank for direct attachment to compatible indicator spindles. The contact point length is 0.5 inches. This type of accessory is commonly installed by machinists, toolroom technicians, quality control inspectors, and field metrologists who rely on consistent, repeatable surface contact when taking measurements on curved, concave, or cylindrical workpiece surfaces.

This contact point is suited for use in industrial manufacturing, machine shops, and inspection environments where dial indicators are used to check runout, concentricity, or surface variation. The cupped ball geometry helps seat the indicator tip accurately on round stock or ball-ended features, reducing tip slip and improving measurement repeatability. It is classified as an AGD Group 1 accessory, aligning with standard dial indicator configurations common in North American precision tooling setups.

Key Features

• Solid carbide construction for wear resistance and long service life
• Cupped ball contact geometry for improved contact on curved or round surfaces
• 3 mm contact ball diameter provides a defined, consistent contact area
• 0.5 inch contact point length suits standard AGD Group 1 dial indicators
• 4-48 threaded shank for direct installation on compatible dial indicator spindles
• AGD Group 1 industry designation ensures broad fitment compatibility

Compatibility

Designed as a replacement or supplemental contact point for AGD Group 1 dial indicators that accept a 4-48 threaded tip. Suitable for use with dial indicators as specified by the manufacturer.

Installation Notes

Installation is performed by hand-threading the 4-48 shank directly into the spindle nose of a compatible dial indicator. Avoid overtightening, as the small thread can be damaged by excessive torque. Ensure the indicator is removed from service and any clamping fixtures are released before swapping contact points. Inspect the mating threads on the indicator spindle for contamination or damage before installation.