Spi 20-346-3 Cupped Ball Contact Point 3mm Dial Indicator

Product Description

The SPI 20-346-3 is a cupped ball contact point designed for use with dial indicators in precision measurement applications. Machined to AGD Group 1 industry standards, this contact point features a ruby ball tip measuring 3 mm in diameter and a 3/4-inch contact point length. The 4-48 threaded shank provides a secure, standard-fit connection to compatible dial indicator stems. Metrology technicians, tool-and-die makers, machinists, and quality control inspectors use this type of contact point when inspecting curved or spherical surfaces where a standard flat point would yield inaccurate readings.

This contact point is suited for precision dimensional inspection tasks in machine shops, manufacturing facilities, and quality labs. The cupped ball geometry is particularly effective when measuring round stock, ball bearings, or concave surfaces. It installs directly into the contact point stem of a compatible AGD Group 1 dial indicator and is a drop-in replacement for worn or damaged contact points on existing instruments.

Key Features

• Ruby ball tip resists wear and maintains dimensional accuracy over repeated use
• 3 mm ball diameter suits curved and spherical surface measurement
• 3/4-inch (0.75 inches) contact point length fits standard AGD Group 1 indicator stems
• 4-48 threaded shank for secure attachment to compatible dial indicator bodies
• Meets AGD Group 1 industry designation for broad indicator compatibility

Compatibility

Designed for use with dial indicators accepting 4-48 threaded contact points per AGD Group 1 industry standards.

Installation Notes

Contact point replacement is performed by machinists or metrology technicians using standard hand tools. Power down any automated measurement fixture before servicing the indicator. Thread the contact point in by hand first to avoid cross-threading, then snug with the appropriate spanner or wrench — do not overtighten the threaded shank. Verify indicator zero after replacing the contact point before returning the instrument to service.