Spi 29-812-5 Class Zz Plus Plug Gage 0.812 Inch

Product Description

The SPI 29-812-5 is a Class ZZ Plus plug gage designed for precision hole inspection in machine shops, toolrooms, and manufacturing environments. It measures bores at a nominal diameter of 0.812 inches with a tolerance of 0.0002 inches, making it suitable for go/no-go inspection of machined holes where close dimensional control is required. The gage body is constructed from steel for durability under repeated use. Machinists, quality technicians, and tool room personnel use plug gages like this one to verify that drilled, reamed, or bored holes fall within specified tolerance limits before parts advance to the next stage of production.

This plug gage is used in production inspection and quality assurance settings where bore diameter must be confirmed to tight tolerances. It is appropriate for general metalworking, automotive component inspection, aerospace fabrication support, and any precision machining operation requiring verification of a 0.812-inch nominal bore. Class ZZ Plus designation indicates the gage meets the tolerance class commonly applied to production-grade inspection work rather than master or reference gage applications.

Key Features

• Nominal measurement diameter of 0.812 inches for direct bore inspection
• Tolerance of 0.0002 inches, meeting Class ZZ Plus accuracy requirements
• Steel construction for wear resistance and dimensional stability
• Single-piece package quantity, allowing individual unit procurement
• Compact and lightweight at 0.2 pounds for easy bench and in-line use

Compatibility

Designed as a production-grade plug gage for inspecting machined holes with a nominal diameter of 0.812 inches in any workpiece material where Class ZZ Plus tolerance standards apply.

Installation Notes

Plug gages are handled and used by machinists and quality control technicians. Before use, clean the gage and the bore being inspected to remove chips, coolant, and debris that could affect the measurement reading. Do not force the gage through a bore under excessive pressure, as this can damage the gage surface and introduce measurement error. Store the gage in its protective case away from temperature extremes to maintain dimensional stability.