Spi 19-397-9 Class Zz Minus Plug Pin Gage 0.397 in

Product Description

The SPI 19-397-9 is a Class ZZ minus plug pin gage with a 0.397-inch diameter, designed for go/no-go dimensional inspection of holes and bores. Class ZZ is the standard tolerance class for plug gages used in inspection and quality control applications where repeatable, reliable measurement is required. This gage carries a minus tolerance of 0.000200 inches, meaning the gage falls just below nominal, which is standard for minus-type plug gages used to verify minimum hole size. Machined from steel, this pin gage is a hand-held tool handled by machinists, quality technicians, and tool room personnel during in-process or final inspection.

This pin gage is suited for use in machine shops, manufacturing facilities, and quality control labs. It is used to verify that a drilled, reamed, or punched hole meets its minimum diameter specification before a part moves to the next stage of production. At 0.397 inches nominal diameter, it fits inspection tasks commonly encountered in general precision machining, fixture building, and assembly verification. It is a single-ended gage appropriate for hand inspection work at a bench or on the floor.

Key Features

• Class ZZ tolerance class — standard for plug gages used in general inspection and quality control
• Minus tolerance configuration at 0.000200 inches — checks minimum hole size acceptance
• 0.397-inch nominal diameter for common bore inspection applications
• Steel construction for durability and dimensional stability under normal shop conditions
• Lightweight at 0.2 pounds — easy to handle during extended inspection tasks

Compatibility

Designed as a standard Class ZZ minus plug pin gage for use with any go/no-go gage handle or holder that accepts a 0.397-inch pin. Compatible with general-purpose gage handle sets used in machine shop and quality control inspection workflows.

Installation Notes

Plug pin gages require no installation in the traditional sense but should be handled and stored carefully to prevent nicks, corrosion, or dimensional changes that affect accuracy. Clean and lightly oil the gage before and after use to prevent rust. Do not force the gage into a bore — a properly sized hole should accept a go gage with light hand pressure only. Calibration and periodic re-inspection against a master reference are recommended per applicable metrology standards.