Spi 3MM/4-48 Test Indicator Ball Contact Point 3mm Steel

Product Description

The SPI 3MM/4-48 is a ball-style contact point designed for use with test indicators in precision measurement applications. It features a 3 mm ball diameter machined from steel, providing durable and consistent contact for surface runout, bore alignment, and dimensional inspection work. This contact point threads onto standard test indicator stems and is a routine replacement or supplemental tip for metrology toolkits. Machinists, quality control technicians, and tool-and-die professionals install these as part of regular indicator maintenance or when switching between measurement tasks requiring a ball-style stylus.

This contact point is suited for use across universal test indicator configurations. The ball contact style is commonly chosen for measuring in grooves, bores, and curved surfaces where a flat or pointed tip would not seat reliably. It is appropriate for both shop-floor and inspection-room environments where standard thread-mount indicator accessories are in use.

Key Features

• 3 mm ball diameter for consistent, repeatable contact on curved and recessed surfaces
• Steel construction provides wear resistance under regular measurement use
• Ball-style geometry suits bore, groove, and contour measurement tasks
• Compatible with universal test indicator configurations
• Lightweight at 0.1 pounds for minimal indicator deflection during setup

Compatibility

Designed for use with universal test indicators accepting standard threaded contact point stems.

Installation Notes

Contact points are installed and removed by hand or with a small wrench on the indicator stem thread — avoid overtightening to prevent thread damage on the indicator body. Ensure the indicator is removed from active fixtures before swapping contact points. No special tools or calibration codes are required, but after replacing a contact point, re-zero the indicator and verify stylus alignment before taking measurements.