Import BDNA-20793 5/8-18 Unf Bottoming Tap 4 Flutes Hss

Product Description

The IMPORT BDNA-20793 is a straight flute bottoming tap designed for cutting internal threads in pre-drilled holes where thread engagement is required close to the bottom of a blind hole. Made from high-speed steel with a gold oxide coating, this tap handles the demands of production and maintenance threading operations. The bottoming chamfer — typically 1 to 2 threads — allows threading to near-full depth, making it the right choice when thread run-out space is limited. With 4 flutes and a right-hand thread configuration, it delivers clean chip control in a wide range of ferrous and non-ferrous materials.

This tap is suited for use in machine shops, maintenance facilities, and general manufacturing environments where precise internal threading is required. It cuts 5/8-18 UNF threads and is commonly used in applications requiring fine-pitch fastening, such as hydraulic fittings, precision assemblies, and mechanical components. The H3 thread limit designation indicates a tolerance class appropriate for standard nut fits, making it a practical choice for general-purpose UNF threading work.

Key Features

• Bottoming chamfer for threading close to the base of blind holes
• High-speed steel construction for durability across common work materials
• Gold oxide coating reduces friction and provides light corrosion resistance
• 4 straight flutes for efficient chip evacuation in through and shallow blind holes
• Right-hand, H3 thread limit for standard UNF tolerance fits
• 5/8-18 UNF thread form for fine-pitch fastening applications

Compatibility

Designed as an OEM-style threading tool for use in standard 5/8-18 UNF tapping applications in ferrous and non-ferrous materials across general machining and maintenance operations.

Installation Notes

Tapping operations should be performed by qualified machinists or maintenance technicians using a proper tapping tool, tap wrench, or CNC machine set to the correct feed rate for the thread pitch. Always use cutting fluid appropriate for the workpiece material to extend tap life and improve thread finish. Ensure the tap is aligned perpendicular to the workpiece before engaging to prevent tap breakage or thread distortion. Back the tap out periodically to clear chips when threading blind holes.