Spi 29-037-9 Class Zz Plus Plug Gage 0.037 in

Product Description

The SPI 29-037-9 is a Class ZZ Plus plug gage designed for precise go/no-go inspection of small-diameter bored holes, drilled passages, and machined apertures. Built from steel, this gage checks a nominal hole diameter of 0.037 inches with a tolerance of 0.0002 inches, meeting Class ZZ Plus accuracy requirements. It is used by machinists, tool-and-die makers, quality control inspectors, and precision shop technicians who need fast, reliable dimensional verification on small features. The compact, single-ended design makes it straightforward to handle during high-frequency inspection routines on the shop floor or in a metrology lab.

This plug gage is suited for inspecting small precision holes in machined components across manufacturing, aerospace, hydraulics, and general metalworking applications. It is appropriate wherever a tight-tolerance bore of 0.037 inches must be verified against print specifications. The Class ZZ Plus designation places this gage in the working-gage category, making it a standard choice for production inspection rather than master or reference gaging.

Key Features

• Nominal measurement diameter of 0.037 inches for small-bore inspection
• Class ZZ Plus tolerance of 0.0002 inches for accurate go/no-go verification
• Steel construction for durability under regular shop use
• Compact single-unit form factor suited to high-frequency production inspection
• Lightweight at 0.2 pounds for easy handheld use

Compatibility

Designed as a working-class plug gage for go/no-go inspection of precision bored holes nominally sized at 0.037 inches in machined parts and assemblies.

Installation Notes

Plug gages are handled and used by machinists and quality control inspectors; no power source or special tooling is required. Keep the gage clean and lightly oiled when not in use to prevent corrosion and wear on the precision ground surface. Do not force the gage into an undersized hole, as this can damage the gage or scratch the bore. Store in a protective case away from abrasive materials to maintain dimensional accuracy.