Spi 21-256-3 Flat Button Contact Point Dial Indicator

Product Description

The SPI 21-256-3 is a flat button contact point designed for use with dial indicators in precision measurement applications. Machined from black oxide steel, this contact point threads onto standard dial indicator stems using a 4-48 thread size, providing a secure and repeatable connection. The flat button profile delivers broad surface contact, making it well suited for measuring flat or slightly irregular workpiece surfaces. At 0.094 inches in contact point length and 5/8 inch in diameter, it conforms to AGD Group 1 industry standards, ensuring compatibility with a wide range of professional-grade dial indicators.

This contact point is a standard accessory component used in machine shops, manufacturing facilities, and precision inspection environments. It is typically installed by machinists, quality control technicians, and tool-and-die professionals who require consistent, reliable surface contact during gaging operations. The flat button style is appropriate for applications where a larger contact surface is needed to reduce point pressure on soft or finished workpiece surfaces.

Key Features

• Flat button contact style provides broad surface contact for flat and near-flat measurement surfaces
• Black oxide steel construction offers durability and corrosion resistance in shop environments
• 4-48 thread size for secure attachment to AGD Group 1 dial indicator stems
• 0.094 inch contact point length suits standard indicator tip clearance requirements
• 5/8 inch diameter button face for reduced point pressure on sensitive workpieces
• Meets AGD Group 1 industry designation for standardized fitment

Compatibility

Designed for use with dial indicators accepting a 4-48 thread contact point, conforming to AGD Group 1 industry standards.

Installation Notes

Installation is performed by machinists or inspection technicians using standard hand tools. Thread the contact point onto the dial indicator stem by hand, then snug gently — overtightening can damage the fine 4-48 threads on the indicator spindle. Ensure the indicator is removed from the gage stand or fixture before swapping contact points to avoid accidental stylus damage or measurement error.