Spi 20-619-3 Ball Point Contact Point Set 22 Pc Agd

Product Description

The SPI 20-619-3 is a 22-piece ball point contact point set designed for use with AGD (American Gauge Design) dial indicators. Each contact point in the set features a 4-48 thread size, which is the standard thread specification for most AGD-style indicator stems. The set gives metrology technicians, machinists, and calibration professionals a range of interchangeable contact tips in a single kit, eliminating the need to source individual points for different measurement applications. Ball point contacts are typically used when measuring on curved surfaces or in situations where a flat or pointed contact would introduce cosine error or damage a workpiece finish.

This contact point set is suited for production floor metrology, quality control inspection, and toolroom applications where AGD dial indicators are in regular use. The 22-piece assortment covers a wide variety of reach and geometry combinations, making it a practical bench stock item for inspection departments and machine shops that run multiple indicator setups across different fixtures and surfaces.

Key Features

• 22 individual ball point contact points included in one set
• 4-48 thread size matches AGD indicator stem standard
• Ball point geometry reduces cosine error on curved and irregular surfaces
• Multiple contact lengths and configurations in a single assortment
• Interchangeable design allows rapid tip swaps between indicator setups

Compatibility

Designed for use with AGD-style dial indicators that accept a standard 4-48 threaded contact stem. Specific compatible indicator models or manufacturers were not stated in the available product data.

Installation Notes

Contact point installation requires only finger-tightening or a small wrench to thread the contact onto the indicator stem — avoid overtightening, which can damage the 4-48 threads on the indicator spindle. Always zero the indicator after changing contact points, as tip length varies between styles and will shift the effective measurement range. Handle ball contacts carefully to avoid nicking the spherical tip surface, which would introduce measurement error.