Spi 29-074-2 Class Zz Plus Plug Gage 0.074 in

Product Description

The SPI 29-074-2 is a Class ZZ Plus plug gage designed for precision dimensional inspection of small-diameter holes and bores. It measures a nominal diameter of 0.074 inches with a tolerance of 0.0002 inches, making it suitable for applications where tight go/no-go verification is required. Constructed from steel for durability and dimensional stability, this plug gage is a standard tool in quality control environments. Machinists, tool-and-die makers, and inspection technicians use this type of gage to verify hole diameter conformance to drawing tolerances on the shop floor or in the inspection room.

Class ZZ Plus plug gages are typically used in production and inspection settings where moderate-precision hole verification is needed. This gage is appropriate for checking drilled, reamed, or broached holes in metal, plastic, or composite workpieces. It is suited for both incoming inspection and in-process quality checks. The small 0.074-inch diameter makes it particularly relevant for tight-tolerance work in aerospace, automotive, and general machining applications where small-bore accuracy is critical.

Key Features

• Class ZZ Plus tolerance rating for reliable go/no-go dimensional verification
• Nominal measurement diameter of 0.074 inches
• Tolerance of 0.0002 inches for precise hole conformance checking
• Steel construction for wear resistance and dimensional stability
• Compact, single-piece form factor suited for small-bore inspection

Compatibility

Designed as a standard Class ZZ Plus plug gage for use in go/no-go inspection of holes and bores nominally sized at 0.074 inches in diameter across a range of machined workpiece materials and industries.

Installation Notes

Plug gages should be handled and stored carefully to prevent damage to the precision-ground surfaces. Clean the gage and the hole being inspected before use to avoid debris-induced measurement error. Do not force the gage into an undersized hole, as this can damage the gage surface and produce inaccurate results. Periodic calibration against NIST-traceable standards is recommended to maintain measurement integrity.