Hertel K008494AS Straight Flute Tap 7/16-20 Unf Bottoming Hss

Product Description

The HERTEL K008494AS is a straight flute bottoming tap designed for cutting internal threads in through-holes and blind holes where threads must extend close to the bottom. Built from high-speed steel (HSS) with a bright, uncoated finish, it produces 7/16-20 UNF right-hand threads across 4 flutes. The H3 thread limit provides a controlled fit tolerance suitable for standard UNF fastener assemblies. With an overall length of 3-5/32 inches, this tap is sized for use in manual tap handles or machine tapping fixtures. Machinists, tool-and-die technicians, and maintenance mechanics routinely specify this configuration when threading steel, aluminum, and similar materials in production and repair work.

This tap is suited for bottoming applications in both job-shop and production environments where a standard taper or plug tap has already started the thread and a full-depth thread to the bottom of a blind hole is required. The straight flute geometry works best in shorter-chipping materials. It is appropriate for use in manual or CNC tapping operations where chip evacuation out of the hole entrance is acceptable.

Key Features

• Bottoming chamfer allows threading to the base of blind holes
• 7/16-20 UNF thread form for fine-pitch unified thread applications
• 4 straight flutes for chip clearing in shorter-chipping materials
• H3 thread limit for consistent fit tolerance with standard UNF fasteners
• High-speed steel construction for durability across a range of workpiece materials
• Bright, uncoated finish suitable for use with cutting oils and standard tap lubricants

Compatibility

Designed as a standard replacement or production tap for applications requiring 7/16-20 UNF bottoming threads in materials compatible with HSS straight flute tooling.

Installation Notes

This tap should be installed in a properly sized tap handle or tapping chuck rated for the tool diameter. Ensure the workpiece is securely fixtured before tapping to prevent tap breakage. Apply appropriate cutting oil or tapping fluid throughout the operation to reduce heat and extend tool life. Inspect the tap for chipping or wear before each use, as a damaged tap can damage the workpiece thread or break in the hole.