Hertel K008317AS Straight Flute Tap 1/4-20 Unc Bottoming Hss

Product Description

The HERTEL K008317AS is a straight flute bottoming tap designed to cut internal threads in pre-drilled holes where full thread depth close to the bottom of a blind hole is required. Made from high-speed steel with a bright/uncoated finish, this tap cuts 1/4-20 UNC right-hand threads with 4 flutes over a 1-inch thread length. The overall length measures 2.5 inches. The H2 thread limit designation indicates a close-tolerance fit suitable for standard fastener applications. This tap is installed by machinists and maintenance trades using a tap wrench or tapping head in drill press and manual setups.

This tap is suited for threading operations in ferrous and non-ferrous metals in manufacturing, maintenance, and repair environments. The bottoming chamfer style allows threading to within 1 to 2 threads of the bottom of a blind hole, making it the correct choice when a plug or taper tap has already started the thread and full depth is needed. It is commonly used in machine shops, fabrication, and field maintenance applications requiring 1/4-20 UNC threads.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• 4 straight flutes for efficient chip evacuation in through and blind hole applications
• High-speed steel construction for durability in general-purpose tapping
• Bright/uncoated finish suitable for use with cutting fluids across a range of materials
• H2 thread limit for standard close-tolerance 1/4-20 UNC thread production
• Right-hand thread direction for standard tapping operations

Compatibility

Designed as a standard replacement or working tap for 1/4-20 UNC bottoming tap applications in tap wrenches, tapping heads, and CNC rigid tapping setups accepting a 0.255-inch shank diameter.

Installation Notes

Installation is performed by machinists or maintenance technicians using a tap wrench or appropriate tapping tool. Always use a cutting fluid or tapping compound appropriate for the workpiece material to extend tool life and improve thread quality. Ensure the pilot hole is drilled to the correct tap drill size for 1/4-20 UNC before tapping. On a bottoming tap, start the thread with a taper or plug tap first, then follow with this tap to reach full thread depth near the hole bottom.