Spi 19-681-6 Class Zz Minus Plug Pin Gage 0.681 in

Product Description

The SPI 19-681-6 is a Class ZZ minus plug pin gage ground to a nominal diameter of 0.681 inches with a minus tolerance of 0.0002 inches. Plug pin gages are precision measuring tools used to verify bore and hole dimensions to a defined tolerance class. This gage is manufactured from steel for durability and dimensional stability under repeated use. Class ZZ is the standard tolerance class for plug gages used in general inspection work where Go/No-Go verification of hole size is required. Machinists, quality control technicians, and tool room professionals use this type of gage to confirm that drilled, reamed, or bored holes fall within acceptable dimensional limits.

This gage is suited for inspection applications in machine shops, manufacturing facilities, and quality assurance environments. It is used to check hole diameters in metal, plastic, and composite workpieces where tight dimensional control is required. The minus designation indicates the gage is ground below nominal, making it appropriate for use as a Go member in Go/No-Go gage setups or as a standalone check gage for lower-limit verification. General-purpose bench inspection and incoming material verification are common use cases.

Key Features

• Nominal diameter of 0.681 inches for precise bore verification
• Class ZZ tolerance classification for general-purpose inspection use
• Minus tolerance ground to 0.0002 inches below nominal
• Steel construction for dimensional stability and wear resistance
• Compact single-piece design for bench or hand-held inspection use

Compatibility

Designed as a general-purpose plug pin gage for use in any inspection setup requiring a 0.681-inch nominal diameter Class ZZ minus gage. Compatible with standard gage handle holders sized for this diameter range.

Installation Notes

Plug pin gages should be cleaned and inspected before each use to remove debris that could affect measurement accuracy. Handle the gage by the knurled handle or shank only to avoid introducing thermal expansion from hand contact on the gage diameter. Store in a protective case away from other tooling to prevent nicks or surface damage. Periodic recalibration against a certified master is recommended to maintain traceability to measurement standards.