Spi 29-137-7 Class Zz Plus Plug Gage 0.137 in Dia

Product Description

The SPI 29-137-7 is a Class ZZ Plus plug gage designed to verify bore and hole diameters to a nominal size of 0.137 inches. Built from steel, it holds a tolerance of 0.0002 inches, making it suitable for go/no-go inspection work in production and quality-control environments. Class ZZ is the standard tolerance class for general-purpose inspection gaging, and the Plus designation indicates the gage is made to the tightest end of that tolerance band. Machinists, quality technicians, and tool-and-die professionals use plug gages like this one to confirm that drilled, reamed, or bored holes fall within specification before parts move to assembly.

This gage is used in shop-floor and inspection-room applications where small-diameter hole verification is required. At 0.137 inches nominal diameter, it is appropriate for checking holes produced by precision drilling or reaming operations in metalworking, manufacturing, and light industrial settings. It is a single-piece, fixed-limit gage intended for manual use with no moving parts, making it fast and repeatable for high-volume inspection tasks.

Key Features

• Nominal measurement diameter of 0.137 inches for precise small-bore inspection
• Class ZZ Plus tolerance of 0.0002 inches for reliable go/no-go verification
• Steel construction for durability and dimensional stability in shop environments
• Fixed-limit design requires no calibration adjustment during use
• Lightweight at 0.2 pounds, easy to handle for repetitive inspection tasks

Compatibility

Designed as a general-purpose fixed-limit plug gage for inspecting holes and bores with a nominal diameter of 0.137 inches in metalworking and precision manufacturing applications.

Installation Notes

Plug gages are handled by quality technicians and machinists and require no installation in the traditional sense. Before use, clean both the gage and the workpiece bore to remove chips, coolant, and debris that could affect the reading. Handle the gage carefully to avoid dropping or striking it, as impact can alter its calibration. Store the gage in its protective case or holder when not in use to prevent corrosion and wear.