Spi 29-561-8 Class Zz Plus Plug Gage 0.561 in Dia

Product Description

The SPI 29-561-8 is a Class ZZ Plus plug gage used to verify the inside diameter of machined holes and bores to a nominal measurement of 0.561 inches. Built from steel, this fixed-limit go gage provides a tolerance of 0.0002 inches, making it appropriate for general-purpose inspection work in production and shop environments. Machinists, quality control technicians, and tool room professionals use plug gages like this one to confirm whether a hole falls within specified limits without the need for graduated instruments. The compact size and straightforward design allow for fast, repeatable checks at the machine or inspection bench.

This plug gage is suited for use in metalworking, manufacturing, and precision machining applications where hole diameter verification is required. It is commonly used during in-process inspection, first-article inspection, and final quality checks on drilled, reamed, or bored features. The 0.561-inch nominal diameter targets a specific hole size that appears frequently in tooling, jig, and fixture work. The steel construction holds up to repeated use in shop floor conditions.

Key Features

• Nominal measurement diameter of 0.561 inches for fixed-limit hole inspection
• Class ZZ Plus tolerance rating of 0.0002 inches for general-purpose go-gage applications
• Steel construction for durability under repeated production use
• Lightweight at 0.2 pounds for easy single-hand operation
• Single-piece packaging suitable for individual replacement or bench stock

Compatibility

Designed as an OEM-style replacement or direct addition to standard plug gage sets used for 0.561-inch nominal bore verification in general machining and inspection applications.

Installation Notes

Plug gages should be handled with clean, dry hands or cotton gloves to prevent corrosion from skin oils. Before use, inspect the gage surface for nicks, burrs, or wear that could affect accuracy. Always bring the workpiece and gage to the same ambient temperature before measuring to avoid thermal expansion errors. Store the gage in a protective case when not in use to maintain its calibrated tolerance.