Spi 29-761-4 Class Zz Plus Plug Gage 0.761 Inch

Product Description

The SPI 29-761-4 is a Class ZZ Plus plug gage designed to verify the inside diameter of bored holes and machined features to a nominal measurement of 0.761 inches. Built from steel, this go/no-go style precision tool maintains a tolerance of 0.0002 inches, making it appropriate for quality control checks in production and job-shop environments. Machinists, toolmakers, and quality technicians use plug gages like this one to confirm that drilled, reamed, or bored holes fall within specified tolerances before parts advance to assembly or final inspection.

This plug gage is suited for use in precision machining, metalworking, and manufacturing inspection settings where hole diameter verification is part of a standard quality process. It is appropriate for both in-process checks and final inspection on steel, aluminum, and other machined workpieces. The compact size and steel construction make it a practical bench tool for inspection departments and floor-level quality checks alike.

Key Features

• Nominal measurement diameter of 0.761 inches for direct hole verification
• Class ZZ Plus tolerance rating of 0.0002 inches for reliable go/no-go inspection
• Steel construction for durability and dimensional stability under shop conditions
• Compact and lightweight at 0.2 pounds for easy handling at the bench or on the floor
• Single-piece packaging suitable for individual tool replacement or kit supplementation

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for any application requiring inspection of a 0.761-inch nominal inside diameter to Class ZZ Plus tolerances.

Installation Notes

Plug gages are hand-held precision instruments and do not require mechanical installation. Before use, clean the gage and the hole being checked to remove chips, coolant, and debris that could affect the measurement. Handle the gage carefully to avoid dropping or striking it, as impact can alter its calibrated diameter. Periodic re-calibration against a certified master is recommended to maintain traceability in regulated inspection environments.