Spi 21-261-3 Flat Button Contact Point 2-1/2 in Dial

Product Description

The SPI 21-261-3 is a flat button contact point designed for use with dial indicators. Machined from black oxide steel, this AGD Group 1 contact point features a 4-48 thread size for secure attachment to compatible indicator spindles. It measures 2.5 inches in diameter with a contact point length of 0.25 inches. The flat button profile is suited for surface measurement applications where a broad, stable contact face is needed. Metrology technicians, machinists, and quality control professionals install this type of contact point when swapping out worn tips or adapting an indicator to a specific measurement task.

This contact point is intended for use with dial indicators in precision measurement settings, including machine shop environments, inspection stations, and dimensional verification setups. The flat button style is commonly selected for measuring flat or near-flat surfaces where a spherical or pointed tip would produce less reliable readings. Its AGD Group 1 designation indicates compatibility with standard AGD-spec dial indicator spindles.

Key Features

• Flat button contact face provides stable, broad surface contact for flat-surface measurement
• Black oxide steel construction for durability and corrosion resistance
• 4-48 thread size for secure spindle attachment
• 2.5 inch diameter contact point head
• Contact point length of 0.25 inches
• AGD Group 1 designation for compatibility with standard dial indicator spindles

Compatibility

Designed for use with dial indicators. AGD Group 1 industry designation applies to standard AGD-spec dial indicator spindles accepting a 4-48 threaded contact point.

Installation Notes

Contact point replacement is typically performed by machinists or metrology technicians using standard hand tools. Before swapping contact points, remove the indicator from any active fixture and ensure no load is applied to the spindle. Thread the contact point carefully by hand first to avoid cross-threading the 4-48 spindle thread, then snug with the appropriate tool without overtightening.