Spi 29-910-7 Class Zz Plus Plug Gage 0.91 Inch

Product Description

The SPI 29-910-7 is a Class ZZ Plus plug gage designed for precision hole measurement in machine shops, quality control labs, and manufacturing environments. Built to a tolerance of 0.0002 inches, this go/no-go style gage confirms whether a drilled or reamed hole at 0.91 inches diameter falls within acceptable limits. The steel construction provides durability and dimensional stability across repeated use cycles. Machinists, tool-and-die technicians, and QC inspectors rely on Class ZZ Plus gages for final inspection of production parts where tight tolerances are critical.

This plug gage is suited for inspecting 0.91 inch diameter holes in precision machined components across light manufacturing, aerospace part fabrication, automotive, and general metalworking applications. It is used at incoming inspection stations, inline quality checks, and final acceptance inspection. The compact size makes it practical for both bench and floor inspection use. Single-piece packaging makes it straightforward to add to an existing gage kit or replace a worn gage in a set.

Key Features

• Class ZZ Plus tolerance rating at 0.0002 inches for reliable go/no-go inspection
• 0.91 inch nominal measurement diameter
• Steel construction for dimensional stability and long service life
• Compact, single-piece design fits standard gage holders and handles
• Suitable for production inspection of drilled, reamed, or bored holes

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for standard Class ZZ Plus gage handle systems accepting 0.91 inch diameter gage members.

Installation Notes

Plug gages are installed and used by machinists, metrology technicians, and QC inspectors. Before use, clean the gage and the hole being checked with a lint-free cloth to remove chips, oil, or debris that could affect measurement accuracy. Do not force the gage member into the hole, as this can damage the gage or the workpiece. Store the gage in a protective case away from other metal tools to prevent surface damage that would affect tolerance integrity.