Spi 29-388-6 Class Zz Plus Plug Gage 0.388 in

Product Description

The SPI 29-388-6 is a Class ZZ Plus plug gage designed for precision go/no-go inspection of 0.388-inch diameter bores and holes. It allows machinists and quality technicians to verify that a drilled, reamed, or machined hole falls within the specified tolerance range. The gage is manufactured from steel for durability and dimensional stability under shop conditions. With a tolerance of 0.0002 inches, this Class ZZ Plus gage meets standard inspection requirements for dimensional verification in production and toolroom environments. It is a direct-use, single-piece inspection tool requiring no setup beyond handling.

This plug gage is used in machine shops, production floors, and toolrooms wherever 0.388-inch bore acceptance testing is required. It is appropriate for inspecting drilled, reamed, punched, or cast holes in metal, plastic, and composite workpieces. Quality control inspectors and machinists performing in-process checks are the primary users. It is suited to both high-volume production inspection and low-volume toolroom verification tasks.

Key Features

• Class ZZ Plus accuracy with 0.0002-inch tolerance for reliable go/no-go inspection
• 0.388-inch nominal diameter targets a common drilled and reamed hole size
• Steel construction provides wear resistance and dimensional stability
• Single-piece design requires no assembly or calibration setup before use
• Lightweight at 0.2 pounds for easy single-hand operation during inspection

Compatibility

Designed as an OEM-style plug gage for go/no-go inspection of 0.388-inch diameter bores across standard machined, drilled, or reamed workpieces in general metalworking and manufacturing applications.

Installation Notes

Plug gages are handled by quality control technicians and machinists and require no permanent installation. Before use, clean the gage and bore surfaces to remove chips, coolant, and debris that could cause false readings or gage wear. Store the gage in a protective case when not in use to prevent nicks and corrosion on the precision ground surface. Periodic recalibration against a reference standard is recommended to maintain inspection accuracy per ASME B89 or applicable metrology standards.