Spi 21-249-8 Flat Contact Point Dial Indicator

Product Description

The SPI 21-249-8 is a flat contact point designed for use with dial indicators in precision measurement applications. Machined from black oxide steel, this contact point threads onto AGD Group 1 dial indicators using a 4-48 thread. The flat contact surface measures 3/16 inches (0.1875 inches) in diameter, and the contact point length is 1/2 inch (0.5 inches). Weighing 0.1 pounds, it is a compact, direct-replacement accessory suited for machinists, tool-and-die makers, and quality control technicians who need a reliable flat-tip configuration for surface or bore measurement work.

This contact point is intended for precision measurement setups where a flat contact profile is required. Typical applications include surface plate inspection, fixture checking, and machine alignment tasks where the standard contact point must be swapped for a flat-tip style. The 4-48 thread is the standard thread used across AGD Group 1 dial indicators, making this a straightforward replacement or spare for shop-floor and inspection-room use alike.

Key Features

• Flat contact point style for consistent surface contact during measurement
• Black oxide steel construction for durability and corrosion resistance
• 4-48 thread — standard for AGD Group 1 dial indicators
• Contact point length of 0.5 inches (1/2 inch) for standard reach
• 3/16 inches (0.1875 inches) diameter contact face
• Lightweight at 0.1 pounds — does not affect indicator spindle movement

Compatibility

Designed for use with AGD Group 1 dial indicators that accept a 4-48 threaded contact point. Verify thread size and group designation on your indicator before installation.

Installation Notes

Contact point replacement on dial indicators is typically performed by metrology technicians or machinists. Before removing or installing a contact point, secure the indicator in a holder or fixture to avoid dropping or damaging the instrument. Thread the contact point in by hand and snug gently — do not over-torque, as the fine 4-48 thread can strip. Verify the indicator reads zero correctly on a reference surface after installation.