Spi 29-434-8 Class Zz Plus Plug Gage 0.434 in

Product Description

The SPI 29-434-8 is a Class ZZ Plus plug gage used to verify bore and hole diameters to a precise tolerance of 0.0002 inches. Built from steel, this go/no-go style gage gives machinists, quality control inspectors, and tool-room technicians a reliable method for checking whether a 0.4340-inch diameter hole meets drawing specifications. Class ZZ gages are the standard working gage grade for production inspection, offering practical accuracy without the added cost of tighter laboratory-grade classes. The compact form and light weight of 0.2 pounds make it easy to handle during high-volume inspection routines.

This plug gage is suited for use in machine shops, manufacturing facilities, and tool rooms where bore diameter verification is part of standard quality control workflow. It is appropriate for checking drilled, reamed, or bored holes in steel, aluminum, plastic, and other common production materials. Typical users include CNC machinists, QC technicians, and tool-and-die makers performing first-article inspection or in-process checks on production runs.

Key Features

• 0.4340-inch nominal diameter for precise bore verification
• Class ZZ Plus tolerance of 0.0002 inches for reliable go/no-go inspection
• Steel construction provides durability and wear resistance in production environments
• Lightweight at 0.2 pounds for comfortable hand use during repetitive inspection tasks
• Single-piece package quantity simplifies procurement for individual gage needs

Compatibility

Designed as a standard Class ZZ Plus plug gage for verifying 0.4340-inch diameter bores in general production and tool-room inspection applications.

Installation Notes

Plug gages are handled by quality control technicians and machinists and require no permanent installation. Keep the gage clean and lightly oiled when not in use to prevent corrosion on the steel surface. Never force the gage into a hole; if resistance is felt, the bore is undersized and should be reworked before re-inspection. Store in a protective case away from heat sources and abrasive materials to maintain calibration integrity.