Spi 20-686-2 Test Indicator Ball Contact Point Steel

Product Description

The SPI 20-686-2 is a steel ball contact point designed for use with test indicators in precision measurement applications. The contact point features a 0.031 inch (0.80 mm) ball diameter and is machined from steel for durability and consistent surface contact. It threads onto compatible test indicator spindles and provides a small, stable contact area suited for measuring in tight bores, contoured surfaces, and hard-to-reach geometry. Licensed metrology technicians, machinists, and quality control professionals install this type of contact point when the standard stylus tip is not appropriate for the workpiece geometry.

This ball contact point is intended for use with Starrett test indicators and similar precision instruments requiring a fine-diameter spherical tip. It is well suited for shop-floor inspection, fixture setup, and surface runout checks on small features where accurate repeatable contact is required. The 0.031 inch ball diameter makes it appropriate for small bores and tight radii that larger contact points cannot access cleanly.

Key Features

• 0.031 inch (0.80 mm) ball diameter for fine-feature contact
• Steel construction for wear resistance and dimensional stability
• Designed for use with Starrett test indicators
• Compact geometry suited for small bores and contoured surfaces
• Sold individually for single-point replacement or supplemental inventory

Compatibility

Designed for use with Starrett test indicators. Verify thread size and spindle fitment against your specific indicator model before installation.

Installation Notes

Contact points are installed and removed by qualified metrology or machining professionals using appropriate spanner tools or finger-tight seating per the indicator manufacturer guidelines. Always zero or re-calibrate the indicator after changing contact points to account for any length offset. Avoid overtightening the contact point onto the spindle thread, as this can damage the indicator mechanism. Ensure the indicator is removed from service and any associated machinery is powered down before swapping contact points.