Spi 29-155-9 Class Zz Plus Plug Gage 0.155 in

Product Description

The SPI 29-155-9 is a Class ZZ Plus plug gage used to verify the diameter of precision bores and holes in machined components. Designed for go/no-go inspection work, this gage checks whether an internal feature falls within specified tolerance. The measurement diameter is 0.155 inches with a tolerance of 0.0002 inches, making it suitable for tight-tolerance quality control in production and toolroom environments. The steel construction provides the durability needed for repeated use on the shop floor. Machinists, quality control technicians, and precision metrology professionals are the primary users of this tool.

This plug gage is used in manufacturing, machining, and inspection settings where small-diameter bore verification is required. It is suited for checking drilled, reamed, or bored holes in metal or plastic components where dimensional conformance to print is critical. Class ZZ Plus gages are typically used for inspection of production parts rather than for setting other measuring instruments. The 0.155-inch diameter range targets small precision bores common in aerospace, automotive, and general machined-part manufacturing.

Key Features

• Class ZZ Plus classification for production-grade bore inspection
• Measurement diameter of 0.155 inches for small precision bores
• Tolerance of 0.0002 inches for tight dimensional verification
• Steel construction for wear resistance and long service life
• Compact, single-unit format suited for bench or floor inspection use

Compatibility

Designed as an OEM-style plug gage for use in any application requiring go/no-go inspection of 0.155-inch diameter internal features in machined components.

Installation Notes

Plug gages are handled and used by machinists and quality control technicians and do not require installation in the traditional sense. Clean the gage and the bore to be checked before use to prevent debris from affecting measurement accuracy. Store the gage in a protective case away from other tooling to prevent surface damage. Follow your facility or shop metrology standards for gage calibration intervals and handling procedures.