Spi 29-294-6 Class Zz Plus Plug Gage 0.294 in Dia

Product Description

The SPI 29-294-6 is a Class ZZ Plus plug gage designed to verify the diameter of machined holes and bores to a high degree of precision. This go/no-go style inspection tool checks whether a hole falls within an acceptable tolerance range, making it a standard instrument in quality control and machining environments. Manufactured from steel, the 29-294-6 measures a nominal diameter of 0.294 inches and holds a tolerance of 0.0002 inches, ensuring consistent and repeatable measurement results. Machinists, quality technicians, and tool room professionals use plug gages like this one during in-process and final inspection of drilled, reamed, or bored holes.

This gage is suited for inspection applications in precision machining, tool and die, and manufacturing quality control environments. The 0.294-inch nominal size makes it appropriate for checking holes in metal components where tight dimensional control is required. It is a single-unit item packaged individually and is intended for bench use or integration into a standard gage set workflow. Both job shop and production floor environments commonly rely on Class ZZ Plus plug gages for final acceptance inspection.

Key Features

• Nominal measurement diameter of 0.294 inches for precise hole inspection
• Class ZZ Plus tolerance of 0.0002 inches for high-accuracy go/no-go gauging
• Steel construction for durability and dimensional stability under shop conditions
• Compact and lightweight at 0.2 pounds for easy single-handed use
• Individual packaging suitable for adding to an existing gage set or tool crib

Compatibility

Designed as an OEM-style inspection gage for use in standard plug gage handle sets and holders compatible with the 0.294-inch nominal diameter range.

Installation Notes

Plug gages should be handled with clean, dry gloves or a gage cloth to prevent thermal expansion from hand heat, which can affect measurement accuracy. Before use, verify that the gage and workpiece are at a stable ambient temperature, typically 68 degrees F per standard metrology practice. Do not force the gage into a hole; apply light, consistent hand pressure only. Store the gage in a protective case away from abrasive materials to maintain the lapped surface finish and dimensional integrity.