Spi 29-689-7 Class Zz Plus Plug Gage 0.689 in

Product Description

The SPI 29-689-7 is a Class ZZ Plus plug gage designed to verify the inside diameter of holes, bores, and machined features to a nominal size of 0.689 inches. Built from steel, this fixed-limit gage provides a straightforward go/no-go check without the need for readout instruments. It is used on the shop floor by machinists, quality technicians, and tool-and-die professionals who need fast, repeatable confirmation that a workpiece meets dimensional tolerance. The 0.689-inch nominal diameter and a tolerance of 0.0002 inches make this gage appropriate for moderate-precision inspection work consistent with Class ZZ standards.

This plug gage is suited for general-purpose inspection in job shops, production machining environments, and maintenance departments. It is used wherever inside diameter verification is required as part of a quality control workflow. The compact size and low weight of 0.2 pounds make it easy to handle at a workbench or alongside machine tooling. Class ZZ is the standard tolerance class for general shop and inspection use, making this gage appropriate for a wide range of hole-checking applications in both ferrous and non-ferrous workpieces.

Key Features

• 0.689-inch nominal measurement diameter for fixed-limit bore inspection
• Class ZZ Plus tolerance grade at 0.0002 inches for reliable go/no-go gauging
• Steel construction for durability and dimensional stability in shop environments
• Lightweight at 0.2 pounds for easy single-hand use during inspection
• No readout instrument required — provides immediate pass/fail result

Compatibility

Designed as a general-purpose Class ZZ plug gage for inside diameter inspection of holes and bores machined to a nominal diameter of 0.689 inches.

Installation Notes

Plug gages are handled and used by quality control technicians and machinists — no power source or calibration instrument is required during normal use. Store the gage in a protective case away from temperature extremes to maintain dimensional stability. Handle with clean, dry hands or inspection gloves to prevent corrosion from skin oils. Verify the gage against a certified master ring gage or calibration standard at regular intervals per your facility quality plan.