Guhring 9039190079380 Spiral Flute Tap 5/16-18 Unc

Product Description

The GUHRING 9039190079380 is a spiral flute tap designed for blind hole threading in alloyed and unalloyed steel. It cuts a 5/16-18 UNC right-hand thread to a 2B class of fit and produces a thread length of 0.551 inches per pass. The modified bottoming chamfer allows threading closer to the bottom of a blind hole than a standard plug tap. Built from cobalt high-speed steel with a bright, uncoated finish, it carries a 40-degree helix angle that efficiently evacuates chips up and out of the hole during the threading operation. Machinists and toolroom technicians use this tap in CNC machining centers, turret lathes, and manual drill presses.

This tap is suited for production and maintenance threading operations in alloyed steel and unalloyed steel workpieces. The modified bottoming chamfer makes it the correct choice when full thread depth must be achieved near the bottom of a blind bore. The fast flute style and 40-degree right-hand helix promote chip flow in materials that produce continuous or stringy chips. Thread limit H4/H5 accommodates standard tolerance requirements for 2B fit fastener applications in both shop and field environments.

Key Features

• Modified bottoming chamfer for threading close to the bottom of blind holes
• 40-degree right-hand helix for efficient upward chip evacuation
• Cobalt HSS construction provides heat and wear resistance in steel applications
• 2B class of fit with H4/H5 thread limit for standard UNC tolerance requirements
• Bright/uncoated finish suitable for use with cutting oils and water-soluble coolants
• 3 flutes with fast flute style for consistent chip flow in ductile materials

Compatibility

Designed for blind hole threading in alloyed steel and unalloyed steel workpieces requiring a 5/16-18 UNC right-hand thread. Thread limit H4/H5 is compatible with standard 2B tolerance class applications.

Installation Notes

This tap is installed and driven by a qualified machinist or toolroom technician. Before threading, verify the pilot hole diameter matches the required tap drill size for a 5/16-18 UNC thread and that the workpiece is securely fixtured. Apply an appropriate cutting fluid for steel; do not run this tap dry. When tapping on power equipment, use a tapping head or torque-limiting chuck to prevent tap breakage in blind holes.