Hertel K008111AS 1/4-20 Unc Bottoming Tap 3 Flutes Hss

Product Description

The HERTEL K008111AS is a straight flute bottoming tap designed to cut full threads close to the bottom of a blind hole in a 1/4-20 UNC thread form. Machined from high-speed steel (HSS) with a bright/uncoated finish, it delivers consistent thread quality across a wide range of workpiece materials. The bottoming chamfer — typically 1 to 2 thread leads — allows threading nearly to the full depth of a blind bore where plug or taper taps cannot reach. With 3 flutes and an H2 thread limit tolerance, this tap suits general-purpose tapping on manual and CNC machines alike. Machinists, tool-and-die workers, and maintenance technicians use this tap where close-tolerance internal threads are required.

This tap is suited for right-hand 1/4-20 UNC threading operations in production and repair environments. Its 1 inch thread length accommodates standard blind hole depths for this thread size, while the 2.5 inch overall length provides adequate clearance in most tap holders and chucks. Typical applications include threading steel, aluminum, cast iron, and similar machinable metals in light manufacturing, maintenance shops, and machine shops.

Key Features

• Bottoming chamfer for threading to the bottom of blind holes
• High-speed steel construction for durability across common workpiece materials
• H2 thread limit tolerance for consistent, close-tolerance 1/4-20 UNC threads
• 3-flute straight flute design provides chip clearance and stable cutting action
• Bright/uncoated finish suitable for general-purpose tapping without coolant-through requirement
• Right-hand thread direction compatible with standard tap handles and tapping heads

Compatibility

Designed as a standard replacement or production tap for any application requiring a 1/4-20 UNC bottoming tap. Fits standard 0.255 inch shank diameter collets, tap chucks, and tap holders sized for 1/4-inch taps.

Installation Notes

This tap should be installed by a qualified machinist or maintenance technician familiar with thread-cutting operations. Always secure the workpiece before tapping and ensure the spindle or tap handle is properly aligned with the pilot hole to avoid tap breakage. Use appropriate cutting fluid for the workpiece material to extend tap life and improve thread finish. When tapping by hand, use a tap wrench sized for the shank diameter and advance with consistent, controlled pressure.