Spi 29-344-9 Class Zz Plus Plug Gage 0.344 in

Product Description

The SPI 29-344-9 is a Class ZZ Plus plug gage designed to verify bore and hole diameters to a nominal size of 0.344 inches with a tolerance of 0.0002 inches. Built from steel, this go/no-go style precision instrument is used in quality control and inspection workflows to confirm whether a drilled, reamed, or machined hole falls within specification. Machinists, tool-and-die workers, and QC inspectors use plug gages like this one as a fast, reliable alternative to dial bore gages when checking high-volume production parts or incoming material.

The 29-344-9 is suited for inspection of small-diameter bores in precision machined components across manufacturing, maintenance, and toolroom environments. Its compact size makes it practical for bench inspection or in-process checking on the shop floor. The Class ZZ Plus tolerance class is appropriate for production gauging where a step up from standard Class ZZ accuracy is required without moving to tighter Class Z or ZZ-minus specifications.

Key Features

• Nominal measurement diameter of 0.344 inches for precise bore verification
• Class ZZ Plus tolerance rating at 0.0002 inches for production-grade accuracy
• Steel construction for durability and resistance to wear during repeated use
• Compact, single-piece design suited for bench or in-process inspection
• Lightweight at 0.2 pounds for easy handling during high-volume inspection tasks

Compatibility

Designed as a direct-use plug gage for any application requiring verification of a 0.344-inch nominal bore diameter where Class ZZ Plus tolerance standards apply.

Installation Notes

Plug gages require no installation but should be handled by trained inspection personnel following established metrology practices. Clean the gage and the bore being checked before use to prevent debris from causing false readings or surface damage. Store the gage in its protective case when not in use to preserve the ground and lapped measuring surfaces. Periodic calibration against certified master rings is recommended to maintain traceable accuracy.