Spi 21-116-9 Test Indicator Ball Contact Point

Product Description

The SPI 21-116-9 is a ball-style contact point designed for use with dial test indicators in precision measurement applications. The contact point features a 2.00 mm (0.078 inches) steel ball tip and an overall contact point length of 0.497 inches. Machined from steel for durability and dimensional stability, it threads into the indicator spindle to establish the tactile contact needed for accurate surface runout, bore alignment, and positional deviation readings. Metrology technicians, machinists, and quality control inspectors install this type of contact point when the application calls for a spherical contact geometry rather than a flat or chisel-style tip.

Ball contact points are commonly used in machine shops, tool rooms, and production inspection environments where surfaces may be curved, angled, or difficult to reach with a standard flat tip. The spherical geometry minimizes the effect of indicator angle on measurement accuracy, making it suitable for measuring in grooves, bores, and contoured surfaces. This contact point is specifically suited for use with Tesa test indicators.

Key Features

• Steel construction for dimensional stability and wear resistance
• 2.00 mm (0.078 inches) ball diameter for precise point contact
• 0.497 inches overall contact point length
• Ball-style tip geometry reduces cosine error on angled measurement surfaces
• Compatible with Tesa test indicators
• Lightweight at 0.1 pounds for minimal indicator loading

Compatibility

Designed for use with Tesa test indicators requiring a standard ball contact point with a 0.078 inches tip diameter.

Installation Notes

Installation is performed by metrology technicians or machinists as part of indicator setup. The contact point threads into the indicator stylus port — ensure the indicator is removed from the measuring stand and isolated from any moving machinery before swapping contact points. Use fingers or the appropriate spanner to tighten to hand-tight; do not overtighten, as excessive force can damage the indicator spindle threads. Verify zero and calibration after any contact point change.