Spi 29-186-4 Class Zz Plus Plug Gage 0.186 in

Product Description

The SPI 29-186-4 is a Class ZZ Plus plug gage used to verify the dimensional accuracy of machined holes and bores. Designed for go/no-go inspection workflows, it checks whether an inside diameter conforms to a specified tolerance. The 29-186-4 measures a nominal diameter of 0.186 inches with a tolerance of 0.0002 inches, making it suitable for precision quality control in manufacturing and machining environments. The steel construction provides durability and dimensional stability under repeated use. Machinists, quality technicians, and tool-and-die professionals use plug gages like this as part of standard incoming and in-process inspection routines.

This plug gage is applied wherever a 0.186-inch diameter bore must be verified against a close tolerance. Typical use cases include production inspection on CNC-machined parts, press-fit bore verification, and toolroom quality checks. Class ZZ Plus gages are generally used for inspection of parts where moderate precision is required, and are appropriate for both shop-floor and inspection-room environments. The compact size and steel body make it easy to handle during high-volume inspection tasks.

Key Features

• Nominal measurement diameter of 0.186 inches for precise bore inspection
• Class ZZ Plus tolerance of 0.0002 inches ensures reliable go/no-go determination
• Steel construction for dimensional stability and long service life
• Lightweight at 0.2 pounds for easy one-handed use during inspection
• Single-piece unit, ready to use out of the package

Compatibility

Designed as an OEM-style inspection tool for use in any application requiring verification of a 0.186-inch diameter bore to Class ZZ Plus plug gage standards.

Installation Notes

Plug gages are used by quality technicians and machinists and require no permanent installation. Handle the gage with clean, dry hands or cotton gloves to prevent corrosion from skin oils. Store the gage in a protective case when not in use to maintain calibration and surface integrity. Periodic recalibration against a certified master is recommended to ensure continued measurement accuracy.