Spi 29-989-1 Class Zz Plus Plug Gage 0.989 in

Product Description

The SPI 29-989-1 is a Class ZZ Plus plug gage designed for precision bore measurement in industrial and manufacturing environments. Built from steel, this fixed-limit gage checks whether a hole falls within a specified dimensional range. The nominal measurement diameter is 0.989 inches with a tolerance of 0.0002 inches, making it suitable for applications that demand tight dimensional control. Machinists, quality control technicians, and tool-room personnel use plug gages as part of standard go/no-go inspection routines to verify hole size without the need for variable measuring instruments.

Class ZZ Plus plug gages are typically used in production inspection settings where holes must be verified to close tolerances before parts proceed to assembly. This gage is suited for checking drilled, reamed, or bored holes in metal components across a range of manufacturing applications. It is appropriate for use in machine shops, fabrication facilities, and quality inspection stations wherever consistent bore verification is required.

Key Features

• Nominal measurement diameter of 0.989 inches for precise bore inspection
• Tolerance of 0.0002 inches meets Class ZZ Plus accuracy requirements
• Steel construction provides durability and wear resistance in production environments
• Fixed-limit design enables fast, repeatable go/no-go inspection
• Compact and lightweight at 0.2 pounds for easy handling at the inspection station

Compatibility

Designed as a standard Class ZZ Plus fixed-limit plug gage for use in bore inspection applications requiring a nominal diameter of 0.989 inches.

Installation Notes

Plug gages should be handled and stored carefully to prevent damage to the precision ground surfaces. Before use, clean both the gage and the workpiece bore to remove chips, coolant, or debris that could affect the measurement. Do not force the gage into the bore; any resistance beyond the expected fit should be investigated before proceeding. Periodic calibration against a certified reference standard is recommended to maintain measurement integrity.