Spi 34-197-4 Plug Thread Gage 1-64 2B No Go

Product Description

The SPI 34-197-4 is a single-end plug thread gage designed to verify that an internally threaded hole does not meet the No Go condition for a 1-64 UNC thread form at 2B tolerance class. Made from steel, this gage is used to inspect threaded holes for oversize or out-of-tolerance conditions, ensuring fastener engagement will meet dimensional specifications. The No Go member rejects threads that have exceeded the maximum material condition limit. Traceability is backed by an NIST certification included with the gage, making it suitable for quality-controlled manufacturing and inspection environments. Machinists, quality technicians, and tooling specialists are the primary users of this instrument.

This gage is used in precision machining, assembly, and inspection applications where 1-64 threads must meet ANSI and NIST standards at the 2B tolerance class. The 2B class is the standard commercial fit for unified inch external and internal threads and is commonly specified for general-purpose fastener applications. The gage ships without a handle; a Size 0 handle is required separately and must be sourced independently. Typical applications include in-process inspection on the shop floor, incoming and outgoing quality checks, and toolroom verification of tapped holes.

Key Features

• No Go member for 1-64 UNC thread at 2B tolerance class
• Steel construction for durability in production inspection environments
• NIST traceability certification included for quality system compliance
• Conforms to ANSI and NIST standards for thread gaging
• Single-end design for straightforward No Go inspection
• Compatible with Size 0 handle (not included)

Compatibility

Designed as a No Go plug thread gage for internally threaded holes with a 1-64 UNC thread form at 2B tolerance class. Requires a separate Size 0 handle for use.

Installation Notes

Thread gages are installed and used by machinists, quality control technicians, and toolroom personnel. Before use, ensure the gage and threaded workpiece are clean and free of chips, cutting fluid residue, or burrs that could cause false readings. The No Go member should not pass fully through a conforming threaded hole; forced entry can damage the gage and invalidate results. Store gages in a protective case away from impact and temperature extremes to maintain calibration integrity.