Spi 20-344-8 Cupped Ball Contact Point M2.5 Ruby

Product Description

The SPI 20-344-8 is a cupped ball contact point designed for use with dial indicators in precision measurement applications. The contact tip is made from ruby, a material chosen for its hardness and wear resistance, which helps maintain consistent accuracy over repeated measurements. The point threads onto the indicator spindle via an M2.5 thread and measures 3 mm in diameter with a contact point length of 7 mm (approximately 0.28 inches). This type of contact point is standard equipment for metrology technicians, machinists, and quality control professionals who require repeatable surface contact during indicator setup and inspection routines.

The 20-344-8 is suited for use in machine shops, manufacturing facilities, and inspection labs where dial indicators are used to verify part dimensions, runout, flatness, or alignment. It conforms to AGD Group 1 industry designation, making it compatible with standard dial indicators that accept AGD-spec contact points. The cupped ball tip style is commonly selected when measuring curved or irregular surfaces where a standard ball or flat tip would not seat consistently.

Key Features

• Ruby contact tip for high wear resistance and long service life
• Cupped ball contact style for stable seating on curved surfaces
• M2.5 thread for standard dial indicator spindle compatibility
• 7 mm contact point length (0.28 inches) for reach in confined measurement areas
• 3 mm tip diameter provides a defined contact footprint
• Meets AGD Group 1 industry designation

Compatibility

Designed for use with dial indicators accepting AGD Group 1 contact points with an M2.5 spindle thread.

Installation Notes

Installation is performed by threading the contact point onto the dial indicator spindle by hand. Use care not to overtighten, as the M2.5 thread on precision instrument spindles can be damaged by excessive torque. Ensure the indicator is removed from active use or secured in a holding fixture before swapping contact points. A contact point wrench appropriate for the spindle size is recommended to avoid damaging the ruby tip during installation.