Spi 29-680-6 Class Zz Plus Plug Gage 0.68 in

Product Description

The SPI 29-680-6 is a Class ZZ Plus plug gage designed to verify the dimensional accuracy of drilled, reamed, or bored holes to a nominal diameter of 0.68 inches. Built from steel, it delivers a tolerance of 0.0002 inches, meeting Class ZZ Plus standards for go/no-go inspection work in production and quality-control environments. Machinists, toolroom technicians, and quality inspectors use this gage to confirm that hole diameters fall within acceptable limits before parts advance to assembly or final inspection. Its compact, lightweight form at 0.2 pounds makes it easy to handle during repetitive inspection cycles.

This plug gage is suited for use in machine shops, manufacturing facilities, and toolrooms where precise hole verification is required. It applies to ferrous and non-ferrous workpieces wherever a 0.68-inch nominal bore must be confirmed to specification. Class ZZ Plus gages are commonly used in less-critical production inspection applications where standard go/no-go gauging satisfies the process requirement rather than master or working-grade tolerances.

Key Features

• 0.68-inch nominal diameter for direct hole inspection at that size
• Class ZZ Plus tolerance of 0.0002 inches for consistent go/no-go gauging
• Steel construction for durability in shop-floor conditions
• Lightweight at 0.2 pounds for comfortable repeated use
• Single-piece package quantity ready for immediate deployment

Compatibility

Designed as an OEM-style replacement or equivalent plug gage for applications requiring a 0.68-inch Class ZZ Plus go/no-go inspection gage in standard production gauging setups.

Installation Notes

Plug gages require no power source but should be handled with clean, dry hands or cotton gloves to prevent corrosion from skin oils. Before use, clean the gage and the bore being inspected to remove chips, coolant, and debris that could cause false readings. Store the gage in a protective case away from other metal tools to prevent nicking or scratching the gage surface, which would compromise tolerance accuracy. Calibration checks against a certified master should be performed periodically per your shop quality plan.