Spi 29-372-0 Class Zz Plus Plug Gage 0.372 Inch

Product Description

The SPI 29-372-0 is a Class ZZ Plus cylindrical plug gage used to verify the diameter of machined holes to a precise tolerance. Manufactured from steel, this plug gage measures hole diameters of 0.372 inches with a tolerance of 0.0002 inches, making it suitable for inspection and quality control work in machine shops, tool rooms, and manufacturing environments. Machinists, quality control inspectors, and toolmakers use plug gages like this one to confirm whether a drilled, reamed, or bored hole falls within an acceptable dimensional range.

Class ZZ Plus plug gages are commonly applied in general-purpose hole inspection where tighter commercial tolerances are required. This gage is appropriate for go/no-go inspection procedures on both ferrous and non-ferrous workpieces. It is a standard single-end plug gage intended for use in production inspection and incoming material verification across a wide range of metalworking and fabrication settings.

Key Features

• 0.372 inch measurement diameter for precise hole inspection
• 0.0002 inch tolerance meets Class ZZ Plus accuracy requirements
• Steel construction for durability and dimensional stability
• Compact and lightweight at 0.2 pounds for easy bench or hand use
• Single-unit packaging suitable for individual tool-room or production use

Compatibility

Designed as a standard Class ZZ Plus plug gage for inspection of 0.372 inch nominal diameter holes in general machining and manufacturing inspection applications.

Installation Notes

Plug gages should be handled with clean, dry hands or lint-free gloves to prevent corrosion from skin oils. Before use, verify the gage and workpiece are at the same ambient temperature to avoid thermal expansion errors. Do not force the gage into a hole; interference fit suggests the hole is undersize. Clean and store the gage in its protective case when not in use to maintain calibration integrity.