Vermont Gage 301000000 Taperlock Thread Plug Gage 1/4-20 Unc

Product Description

The VERMONT GAGE 301000000 is a Taperlock Thread Plug Gage configured as a NoGo (Minus) member for inspecting 1/4-20 UNC 3B internal threads. It checks the pitch diameter and functional thread form to confirm that a threaded hole does not exceed the maximum material condition limit. The NoGo plug has a length of 0.3125 inches and a pitch diameter of 0.2211 inches. Machinists, quality control inspectors, and precision manufacturing technicians use this gage as part of a go/no-go inspection routine on internally threaded components.

This gage is suited for production and inspection environments where 1/4-20 UNC Class 3B thread tolerances must be verified. Class 3B is a tight-tolerance fit class commonly specified for aerospace, defense, and high-precision mechanical assemblies. The Taperlock handle design allows the gage member to be seated securely in a standard Taperlock handle, which is purchased separately. The gage ships with a certificate of accuracy and is marked with nominal size, threads per inch, class of fit, and pitch diameters. One line of additional custom marking up to 25 characters is available at no extra charge.

Key Features

• NoGo (Minus) member checks that internal thread pitch diameter does not exceed maximum material condition
• Configured for 1/4-20 UNC 3B thread form and tolerance class
• NoGo gage length of 0.3125 inches with a pitch diameter of 0.2211 inches
• Taperlock design seats into a standard Taperlock handle for secure, repeatable inspection
• Supplied with a certificate of accuracy
• Marked with nominal size, threads per inch, class of fit, and pitch diameters

Compatibility

Designed for use with standard Taperlock-style gage handles sized for 1/4-20 UNC thread plug gages. The NoGo member pairs with a corresponding Go plug gage to complete a full go/no-go inspection set for 1/4-20 UNC 3B internal threads.

Installation Notes

Thread plug gages are installed and used by machinists or quality inspectors in accordance with ASME B1.2 gaging standards. Ensure the threaded workpiece is clean and free of chips or debris before gaging to avoid false rejections or gage wear. Insert the gage member with light hand pressure only - never force the gage into the thread. Periodically check the gage against a master setting ring or calibration standard to confirm continued accuracy.