Spi 29-057-7 Class Zz Plus Plug Gage 0.057 Inch

Product Description

The SPI 29-057-7 is a Class ZZ Plus plug gage designed for precision go/no-go inspection of small-diameter holes and bores. Built from steel, this gage checks that a hole measures 0.057 inches in diameter within a tolerance of 0.0002 inches. Class ZZ is the standard commercial-grade tolerance class for plug gages, making the 29-057-7 appropriate for production inspection work where consistent dimensional verification is required. Machinists, quality control technicians, and tool room personnel use plug gages like this one as part of routine in-process and final inspection procedures.

This gage is suited for verifying small-diameter features in machined components across general manufacturing, tool and die, aerospace, and automotive applications. The 0.057-inch diameter range addresses fine-bore inspection needs that are common in precision machined parts where hole size directly affects fit, function, and assembly. It is used at inspection stations, machine-side, or in tool rooms where tight dimensional control is maintained.

Key Features

• Class ZZ Plus tolerance class for commercial-grade precision inspection
• 0.057-inch nominal diameter for fine-bore go/no-go checking
• Tolerance of 0.0002 inches ensures repeatable dimensional verification
• Steel construction provides durability for repeated use in production environments
• Single-piece packaging suitable for individual replacement or toolroom stocking

Compatibility

Designed as a standard Class ZZ Plus plug gage for go/no-go inspection of 0.057-inch diameter holes in machined components across general manufacturing and precision fabrication environments.

Installation Notes

Plug gages are handled and used by quality control technicians and machinists following standard metrology practices. Before use, clean the gage and the bore being inspected to remove chips, coolant, and debris that could affect readings. Do not force a plug gage into an undersized hole, as this can damage the gage surface and compromise calibration. Store the gage in its case or a protected location to prevent corrosion and surface wear between uses.