Spi 19-837-4 Class Zz Minus Plug Pin Gage 0.837 in

Product Description

The SPI 19-837-4 is a Class ZZ minus plug pin gage machined from steel, designed to verify that a hole or bore meets minimum acceptable size. At 0.837 inches in diameter with a tolerance of 0.0002 inches, this gage confirms whether a feature is within specification on the minus side of the tolerance band. Class ZZ is the standard tolerance class for workshop-grade go/no-go gaging applications. Machinists, tool-and-die makers, and quality control technicians use plug gages like this one during in-process inspection and final part verification.

This plug pin gage is suited for use in machine shops, production floors, and quality inspection stations where accurate hole size verification is required. It is appropriate for checking drilled, reamed, or bored holes in metal, plastic, or composite workpieces. The minus designation means the gage is ground to the lower boundary of the nominal diameter, making it the go member in a standard go/no-go gage pair. Single-piece packaging makes it easy to add to an existing gage set or replace a worn member.

Key Features

• Class ZZ tolerance class for general workshop and production inspection use
• Minus designation confirms minimum acceptable hole size in go/no-go applications
• 0.837 inch nominal diameter with 0.0002 inch tolerance for precise measurement
• Steel construction for durability and dimensional stability under normal shop conditions
• Single-piece quantity for individual replacement or kit building

Compatibility

Designed as an OEM-style replacement or standalone addition for Class ZZ plug gage sets used in standard workshop hole inspection applications.

Installation Notes

Plug pin gages should be handled with clean, dry hands or cotton gloves to prevent corrosion from skin oils. Before use, clean the gage and the feature being checked with a lint-free cloth to remove chips, coolant, and debris. Apply light gage oil for storage to protect the ground surface. Gage handling and storage practices should follow ASME B89.1.5 guidelines for pin gage care and calibration intervals.