Spi 29-404-1 Class Zz Plus Plug Gage 0.404 in

Product Description

The SPI 29-404-1 is a Class ZZ Plus plug gage designed to inspect and verify hole diameters to a nominal size of 0.404 inches with a tolerance of 0.0002 inches. Manufactured from steel, this go/no-go style precision instrument provides a reliable, repeatable check for bore diameter acceptance during production, inspection, or quality control operations. Class ZZ Plus gages meet standard tolerance grades for inspection of work-part holes and are a common tool in machine shops, manufacturing facilities, and precision fabrication environments. Machinists and quality technicians use plug gages of this type as a fast alternative to indicating bore gages when a simple pass/fail check is required.

This plug gage is suited for use in any precision measurement application where a 0.404-inch nominal hole diameter must be verified. Typical install scenarios include incoming inspection of machined components, in-process quality checks on production lines, and final verification before assembly. The steel construction holds up under regular shop-floor use and maintains gage integrity across repeated insertions.

Key Features

• Nominal diameter of 0.404 inches for precise hole-size verification
• Tolerance of 0.0002 inches meeting Class ZZ Plus gage standards
• Steel construction for durability and dimensional stability under shop conditions
• Compact and lightweight at 0.2 pounds for easy single-handed use
• Go/no-go style check provides fast pass/fail results without readout interpretation

Compatibility

Designed as an OEM-style precision inspection tool for any application requiring verification of a 0.404-inch nominal bore diameter in accordance with Class ZZ Plus gage tolerances.

Installation Notes

Plug gages are used by machinists and quality control technicians and require no installation in the traditional sense. Before use, ensure the gage and the workpiece bore are clean and free of chips, coolant, or debris that could affect the measurement result. Never force a plug gage into a bore; insertion should be smooth and without lateral pressure to avoid gage wear or damage to the workpiece. Store the gage in a protected case and handle with clean hands or lint-free gloves to prevent corrosion and maintain calibration integrity.