Spi 20-336-4 Cupped Ball Contact Point Dial Indicator

Product Description

The SPI 20-336-4 is a cupped ball contact point designed for use with dial indicators in precision measurement applications. Manufactured from solid carbide, it delivers consistent, wear-resistant contact across repeated measurement cycles. The M2.5 threaded shank provides a secure, standard-fit connection, while the 0.28-inch (7 mm) contact length and 3 mm ball diameter are sized to AGD Group 1 specifications. Metrology technicians, machinists, and quality control professionals rely on this style of contact point when checking part geometry, runout, or surface variation with dial indicators.

This contact point is suited for shop floor and laboratory environments where dial indicators are used for dimensional inspection, fixture setup, or machine calibration. The cupped ball geometry concentrates the measurement contact at a defined point, making it appropriate for flat, curved, and contoured surfaces. Its solid carbide construction resists abrasion when used on hardened workpieces or abrasive materials encountered in general machining and quality inspection workflows.

Key Features

• Solid carbide construction for wear resistance during repeated measurement use
• M2.5 threaded shank for standard dial indicator compatibility
• Cupped ball contact geometry suitable for flat and contoured surfaces
• Contact length of 0.28 inches (7 mm) to AGD Group 1 specification
• 3 mm ball diameter for focused, repeatable contact point

Compatibility

Designed for use with dial indicators accepting M2.5 threaded contact points, conforming to AGD Group 1 industry designation.

Installation Notes

Installation is performed by threading the M2.5 shank directly into the dial indicator spindle by hand or with the appropriate small wrench — avoid overtightening, which can damage the indicator spindle threads. Ensure the indicator is removed from service and the measurement stem is fully retracted before swapping contact points. Inspect the carbide tip for chips or flat spots before use, as contact point damage will introduce measurement error.