Spi 20-700-1 Dial Drop Indicator 0.5 in 0.001 Grad

Product Description

The SPI 20-700-1 is a dial drop indicator designed for precise linear measurement in machine shop, tool room, and quality control applications. It offers a 0.5 inch total measurement range with a 0.001 inch graduation, allowing technicians to detect small deviations in surface runout, alignment, and part geometry. The 2.25 inch diameter white dial features dual reading scales — 0-100 and 0-50-0 — with a built-in revolution counter to track travel across multiple rotations. The housing is rigid, forged brass, and the stem diameter measures 0.375 inches, fitting standard AGD-compatible indicator holders and magnetic bases. A certificate of calibration traceable to NPL is included with each unit.

This indicator suits general-purpose precision measurement tasks in manufacturing, machining, and inspection environments. It is used by machinists, quality control inspectors, and tooling technicians for setups requiring repeatable, traceable measurements. The flat lug back and included lug back mounting option expand compatibility with a range of indicator stands and fixtures. Tolerance pointers are included for quick visual pass/fail assessment during inspection routines.

Key Features

• 0.5 inch measurement range with 0.001 inch graduation for fine linear measurement
• Dual dial reading scales: 0-100 and 0-50-0 for bidirectional reading convenience
• Built-in revolution counter tracks full rotations across the measurement range
• Rigid, forged brass housing for durability in shop environments
• Flat and lug back design supports multiple mounting configurations
• Includes certificate of calibration traceable to NPL and tolerance pointers

Compatibility

Meets AGD Group 2 standards and ASME B89.1.10M-2001 specifications. The 0.375 inch stem diameter fits standard AGD-compatible indicator holders, magnetic bases, and universal indicator stands used in machine shop and inspection setups.

Installation Notes

Installation and use should be performed by a qualified machinist, metrologist, or quality technician familiar with precision measuring instruments. Secure the indicator in a compatible holder or magnetic base before zeroing the dial. Avoid side-loading the spindle during measurement, as this can introduce error and cause premature wear. Store the indicator in its case when not in use to protect the calibration and mechanism.