Spi 23-188-6 Truncated Taperlock Thread Plug Gage 5/8-11 Unc

Product Description

The SPI 23-188-6 is a truncated taperlock thread plug gage designed to verify internal thread conformance on 5/8-11 UNC fastener holes. It includes both Go and No Go members, allowing machinists and quality inspectors to confirm that a tapped hole meets Class 2A tolerance limits in a single setup. The gage is manufactured from tool steel for hardness and wear resistance. The taperlock design seats the gage members securely into a standard 3-inch handle, which is included. This tool is used on the shop floor, at inspection stations, or in receiving inspection for production threading operations.

This gage is suited for production environments where 5/8-11 UNC threads are cut by tapping, thread milling, or thread forming. Class 2A is the most common tolerance class for general-purpose external threads, making this gage applicable to a wide range of fastener and assembly applications in manufacturing, machining, and mechanical maintenance. Machinists, quality control technicians, and tool room personnel are the primary users of this type of gage.

Key Features

• Go and No Go members included for complete Class 2A UNC thread verification
• Truncated taperlock design for secure, repeatable seating in standard handles
• Tool steel construction for long service life in production use
• 3-inch handle included — no separate handle purchase required
• Thread size 5/8-11 UNC for common fastener and tapped-hole inspection

Compatibility

Designed as an OEM-style replacement or direct-use gage for standard taperlock handle systems accepting 5/8-11 UNC Class 2A Go No Go gage members.

Installation Notes

Thread plug gages should be handled and stored with care to protect the precision-ground gage members from nicks, corrosion, and wear. Ensure the taperlock gage members are fully seated and locked in the handle before use. Clean and lightly oil gage members after each use to maintain calibration life. Periodic recalibration against NIST-traceable masters is recommended per ASME B1.2 gage practice guidelines.