Spi 29-899-2 Class Zz Plus Plug Gage 0.899 in

Product Description

The SPI 29-899-2 is a Class ZZ Plus plug gage designed to verify bore and hole dimensions to a nominal diameter of 0.899 inches. Built from steel, it delivers a tolerance of 0.0002 inches, making it suitable for go/no-go dimensional inspection work in manufacturing, machining, and quality control environments. Class ZZ is the standard tolerance class for plug gages used in production inspection, and the Plus designation indicates the gage is made to the upper half of the tolerance band. Machinists, quality technicians, and tool room professionals use plug gages like this one to confirm that drilled, reamed, or bored holes fall within specification before parts move to the next stage of production.

This gage is suited for use on precision machined components where hole diameter verification is required. It is appropriate for production floor inspection, incoming inspection, and tool qualification applications across metalworking, fabrication, and general manufacturing shops. At 0.2 pounds, it is a lightweight hand tool that integrates easily into standard inspection workflows without specialized fixtures or setups.

Key Features

• Nominal measurement diameter of 0.899 inches for precise hole gauging
• Tolerance of 0.0002 inches for high-accuracy go/no-go inspection
• Class ZZ Plus designation — manufactured to the upper half of the ZZ tolerance band
• Steel construction for durability and dimensional stability in shop environments
• Lightweight at 0.2 pounds for comfortable single-hand use during inspection

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for production and quality inspection applications requiring a 0.899-inch nominal bore diameter check.

Installation Notes

Plug gages are hand tools used by quality technicians and machinists and require no installation in the traditional sense. Before use, clean both the gage and the bore being inspected to remove chips, coolant, and debris that could affect the reading. Store the gage in its case when not in use and avoid dropping or striking the gage, as impact can alter the measuring surface. Periodic recalibration against traceable standards is recommended to maintain measurement integrity over time.