Spi 29-373-8 Class Zz Plus Plug Gage 0.373 in

Product Description

The SPI 29-373-8 is a Class ZZ Plus plug gage designed to verify hole diameters with a nominal measurement diameter of 0.373 inches and a tolerance of 0.0002 inches. Constructed from steel, this go/no-go style gage provides a reliable reference for dimensional inspection in production and quality control environments. Class ZZ designates this as a working-grade gage suitable for inspecting finished parts, and the Plus designation indicates the tolerance offset is applied in the positive direction relative to nominal. Machinists, toolmakers, and quality technicians use plug gages like this one to confirm bore diameter compliance without the need for elaborate measurement setups.

This plug gage is used in machine shops, manufacturing facilities, and precision fabrication environments where hole diameter verification is part of a standard inspection process. It is appropriate for incoming inspection, in-process checks, and final acceptance of drilled, reamed, or bored holes at the 0.373-inch nominal diameter. The compact form factor and steel construction make it well suited to floor-level production inspection as well as bench-level quality lab use.

Key Features

• Nominal measurement diameter of 0.373 inches for direct hole verification
• Tolerance of 0.0002 inches meets Class ZZ Plus working-gage standards
• Steel construction provides durability and wear resistance in production environments
• Go/no-go form factor enables fast pass-fail inspection without calculation
• Compact, single-piece design suits both bench and floor inspection use

Compatibility

Designed as a working-grade plug gage for inspecting bored, drilled, or reamed holes at a nominal diameter of 0.373 inches in accordance with Class ZZ Plus tolerance standards.

Installation Notes

Plug gages are handled and used by machinists, toolmakers, and quality control technicians. Before use, clean both the gage and the part bore to remove chips, coolant, and debris that could cause false readings or accelerate gage wear. Apply light gage oil if recommended by your quality procedures to protect the gage surface. Store the gage in its protective case when not in use to prevent damage to the precision-ground surface.