Spi 20-690-4 Ball Contact Point Carbide 0.078 in

Product Description

The SPI 20-690-4 is a carbide ball contact point designed for use with test indicators in precision measurement applications. This contact point features a 2.00 mm (0.078 inch) ball diameter and is constructed from carbide for durability and wear resistance in repeated contact cycles. It is used by machinists, metrologists, and calibration technicians who require accurate surface contact during runout, alignment, or tolerance checks. The small ball tip allows access to tight bores, slots, and contoured surfaces where flat or pointed styli cannot reach reliably.

This contact point is suited for shop floor and lab environments where high-precision dimensional measurement is performed. It is a direct replacement or supplemental contact point for technicians working with Starrett test indicators that accept standard contact point threads. Typical applications include checking runout on shafts, verifying bore alignment, and measuring surface deviation on machined parts. The carbide construction holds up in abrasive environments and maintains tip geometry over extended service life.

Key Features

• Carbide ball tip resists wear during high-cycle measurement tasks
• Ball diameter of 0.078 inches (2.00 mm) for access to fine features and curved surfaces
• Compact form factor suited for confined measurement areas
• OEM-style replacement contact point for Starrett test indicators
• Consistent tip geometry supports repeatable measurement accuracy

Compatibility

Designed for use with Starrett test indicators that accept standard contact point configurations.

Installation Notes

Contact points are installed and removed by a qualified technician or metrologist using the appropriate wrench or driver to avoid damaging the indicator spindle threads. Handle carbide tips carefully to prevent chipping on hard surfaces. Ensure the indicator is zeroed and calibrated after replacing the contact point to confirm measurement accuracy.