Spi 29-309-2 Class Zz Plus Plug Gage 0.309 in

Product Description

The SPI 29-309-2 is a Class ZZ Plus plug gage used to verify the diameter of machined holes to a precise tolerance of 0.0002 inches. Manufactured from steel, this go/no-go style gage is a standard tool in quality control, inspection, and production environments where hole size must be confirmed to tight specifications. At 0.309 inches in diameter, the 29-309-2 is suited for small-bore inspection tasks common in machine shops, tool rooms, and light manufacturing facilities. Machinists, quality inspectors, and tooling technicians rely on plug gages like this to confirm dimensional conformance without requiring complex measurement setups.

This plug gage is used in applications where hole diameter verification is required at or near 0.309 inches. Typical use cases include incoming inspection of drilled or reamed holes, in-process checks on machined components, and final inspection before assembly. Class ZZ Plus tolerance rating makes it appropriate for general-purpose inspection work where high production volumes call for fast, repeatable go/no-go checks rather than variable measurement instruments.

Key Features

• 0.309 inch nominal diameter for small-bore hole inspection
• Class ZZ Plus tolerance rating at 0.0002 inches for general-purpose inspection
• Steel construction for durability in production and tool room environments
• Compact and lightweight at 0.2 pounds for easy handling during inspection
• Single-piece package quantity suitable for individual technician use

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for general-purpose inspection of holes with a nominal diameter of 0.309 inches in standard machining and quality control applications.

Installation Notes

Plug gages are handled and used by machinists, quality inspectors, and metrology technicians. Store the gage in a clean, dry environment and handle it with clean hands or lint-free gloves to prevent corrosion and contamination that can affect accuracy. Do not force the gage into a hole; apply only light, consistent hand pressure to avoid wear on the gage or damage to the part being inspected. Periodically check the gage itself against a calibration standard to confirm it remains within tolerance.