The Hertel Extension Tap is a precision machining tool designed for creating threaded holes in materials. This 5/16-18 UNC tap features 4 flutes and an H3 design with a bright, uncoated finish for optimal performance. Crafted from high-speed steel, this standard hand tap with plug chamfer ensures durability and consistent results in threading applications. The tap measures 4 inches in overall length (OAL) and provides a 3B class of fit, making it suitable for general-purpose threading tasks. Manufactured by MSC Industrial under the Hertel brand, this extension tap (Part #G837610) is engineered to deliver reliable performance for professional machinists and industrial applications. The extended length design allows for reaching deeper into workpieces when standard taps won't suffice, making it an essential addition to any machinist's toolbox.