Spi 34-256-8 Plug Thread Gage 1/4-32 6H Single End Go

Product Description

The SPI 34-256-8 is a single-end Go plug thread gage designed to verify internal thread dimensions on 1/4-32 threaded features to the 6H tolerance class. Made from steel, this gage is used to confirm that a tapped hole or internally threaded component falls within the acceptable dimensional range for a mating fastener or fitting. It is calibrated to ANSI and NIST standards and ships with a traceability certification referenced to NIST, making it suitable for use in quality control environments where documented traceability is required. A size 1 handle is required for use but is sold separately. Inspection technicians, machinists, and quality engineers are the primary users of this tool.

This gage is appropriate for shops and inspection departments performing thread verification on precision components with 1/4-32 UNS or similarly specified fine-thread forms. The Go member checks that the thread falls within the minimum material condition, confirming that a conforming mating part will assemble without interference. It is well-suited for applications in aerospace, hydraulic fittings, instrumentation, and other industries where fine-pitch threaded features require documented dimensional verification. The single-end design is compact and straightforward to use with a standard cylindrical handle.

Key Features

• Go member verifies minimum material condition on 1/4-32 internal threads
• 6H tolerance class per ANSI standards for precision thread inspection
• Steel construction for durability and dimensional stability
• NIST-traceable traceability certification included
• Single-end design for simple, efficient inspection workflow
• Compatible with size 1 cylindrical gage handles (handle not included)

Compatibility

Designed for use with size 1 plug gage handles to inspect 1/4-32 internally threaded components to the 6H tolerance class per ANSI standards.

Installation Notes

This gage is used by machinists, quality technicians, and inspection personnel and does not require power or mechanical installation. Before use, confirm the correct handle size is assembled securely and that the gage and workpiece are clean and free of chips or debris. Do not force the Go member through a thread; smooth hand engagement under light pressure is correct practice. Store the gage in its case or a protected environment to prevent corrosion and dimensional damage.