Spi 21-259-7 Flat Button Contact Point Dial Indicator

Product Description

The SPI 21-259-7 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 directly onto compatible dial indicators using a 4-48 thread, providing a stable, low-profile sensing surface for accurate linear measurement readings. The flat button geometry distributes contact pressure evenly across a 1.5-inch diameter face, making it well-suited for workpieces with broad, flat surfaces. At 0.25 inches in contact point length, it fits within the AGD Group 1 standard used widely in machining, inspection, and metrology environments. Machinists, quality control technicians, and tool-and-die professionals are the typical end users.

This contact point is intended for installation on dial indicators in shop-floor measurement setups, inspection stations, and fixture-based gauging applications. It is suited for both manual hand-gauging and indicator-in-fixture configurations. Wherever a flat, broad contact surface is needed to measure soft materials, large flat surfaces, or to reduce point-contact marking on finished parts, the flat button style is the appropriate choice over a standard ball-end or pointed tip.

Key Features

• Flat button contact style distributes load evenly across a 1.5-inch diameter face
• Black oxide steel construction provides hardness and corrosion resistance
• 4-48 thread fits AGD Group 1 dial indicators
• 0.25-inch contact point length for compact, low-profile fitment
• Meets AGD Group 1 industry designation for standardized interchangeability

Compatibility

Designed for use with dial indicators accepting a 4-48 threaded contact point, conforming to AGD Group 1 specifications. Specific dial indicator model compatibility should be confirmed against the indicator manufacturer's thread and contact point specification before installation.

Installation Notes

Contact points should be installed and removed by hand or with an appropriate spanner wrench to avoid cross-threading or over-torquing the 4-48 thread. Ensure the dial indicator stem is clean and free of debris before threading on the contact point. Always zero the indicator after swapping contact points, as point geometry changes affect the reference datum. This work is typically performed by machinists or metrology technicians without specialized tooling beyond a clean work surface and calibrated reference gauge.