Spi 29-012-2 Class Zz Plus Plug Gage 0.012 in

Product Description

The SPI 29-012-2 is a Class ZZ Plus plug gage used to verify bore and hole diameters to a high degree of dimensional accuracy. Manufactured from steel, this gage checks a nominal diameter of 0.012 inches with a tolerance of 0.0002 inches, making it suited for precision inspection work in manufacturing, toolroom, and quality-control environments. Class ZZ Plus gages meet established go/no-go inspection standards and are a standard tool for machinists, metrologists, and quality technicians who require reliable, repeatable measurement of small-diameter features.

This plug gage is intended for use in precision measurement applications where small-bore diameter verification is required. It is commonly used in machining shops, toolrooms, and production inspection stations to confirm that drilled, reamed, or machined holes fall within specified dimensional tolerances. The 0.012-inch diameter makes it appropriate for inspecting very fine bores typical in precision components, nozzles, or small-diameter orifice applications.

Key Features

• Nominal measurement diameter of 0.012 inches for fine-bore inspection
• Tolerance of 0.0002 inches for precise go/no-go verification
• Steel construction for durability and dimensional stability
• Class ZZ Plus classification meets standard inspection-grade requirements
• Compact, single-unit package suitable for individual toolroom use

Compatibility

Designed as a standard Class ZZ Plus plug gage for use with any go/no-go inspection system or gage handle that accepts 0.012-inch diameter plug gage wire inserts.

Installation Notes

Plug gages should be handled with clean, dry hands or inspection gloves to prevent corrosion from skin oils. Store in a protective case away from other tooling to avoid damage to the gage surface. Before use, confirm the gage and workpiece are at the same ambient temperature to avoid thermal expansion errors. Calibration and use should follow applicable ASME or ISO dimensional measurement standards as required by your quality program.