Spi 29-075-9 Class Zz Plus Plug Gage 0.075 Inch

Product Description

The SPI 29-075-9 is a Class ZZ Plus plug gage machined from steel, designed to verify hole diameters with a nominal measurement of 0.075 inches and a tolerance of 0.0002 inches. Plug gages of this class are used for go/no-go dimensional inspection in precision machining, manufacturing, and quality control environments. The tight tolerance makes this gage suitable for checking bores and drilled holes where close-fit assembly is required. Machinists, quality technicians, and tool-and-die professionals rely on Class ZZ Plus gages for fast, repeatable pass/fail verification without the need for electronic measuring equipment.

This plug gage is intended for precision inspection work in machine shops, fabrication facilities, and production environments where small-diameter hole verification is part of the quality control process. It is well suited for checking pilot holes, dowel pin bores, and similar features in ferrous and non-ferrous workpieces. The compact size and light weight make it practical for bench inspection as well as in-process checks on the shop floor.

Key Features

• Nominal measurement diameter of 0.075 inches for small-bore inspection
• Class ZZ Plus tolerance of 0.0002 inches for reliable pass/fail gauging
• Steel construction for durability and wear resistance in production use
• Lightweight at 0.2 pounds, suited for handheld use
• Single-piece unit ready for immediate use without additional setup

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for precision inspection applications requiring a 0.075-inch nominal bore diameter check in Class ZZ Plus tolerance grade.

Installation Notes

Plug gages are handled and used by machinists and quality control technicians following standard metrology practices. Keep the gage clean and lightly oiled when not in use to prevent corrosion and maintain accuracy. Do not force the gage into an undersized bore, as this can damage the gage surface and compromise measurement integrity. Store in a protective case away from heat sources and abrasive materials to preserve tolerance accuracy.