Import BDNA-20789 Straight Flute Tap 3/8-24 Unf Bottoming Hss

Product Description

The IMPORT BDNA-20789 is a bottoming-style straight flute tap designed for cutting internal threads in through-holes and blind holes where full thread engagement close to the bottom is required. Manufactured from high-speed steel (HSS) with a gold oxide coating, this tap produces 3/8-24 UNF right-hand threads and features four straight flutes for efficient chip clearance in a wide range of ferrous and non-ferrous materials. The H3 thread limit designation provides a controlled tolerance class suitable for standard UNF thread fits. Licensed machinists, maintenance mechanics, and tool-and-die professionals use this tap for precision threading operations in production and repair environments.

This tap is suited for use in both manual hand-tapping and low-speed machine tapping applications. The bottoming chamfer — typically 1 to 2 thread lead — allows threading to 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 required. It is commonly used in metal fabrication shops, industrial maintenance settings, and general machining work where 3/8-24 UNF thread specifications are called out on engineering drawings.

Key Features

• 3/8-24 UNF thread form with right-hand thread direction for standard fastener applications
• Bottoming chamfer style allows threading to the base of blind holes
• Four straight flutes provide chip clearance and work well in through-hole and short blind-hole applications
• High-speed steel construction offers durability across a range of common workpiece materials
• Gold oxide coating provides light corrosion resistance and reduces friction during cutting
• H3 thread limit ensures a controlled tolerance class for reliable thread fit

Compatibility

Designed as a standard replacement or working tap for any application requiring 3/8-24 UNF internal threads; compatible with standard tap handles, T-handle wrenches, and low-speed machine tapping fixtures that accept straight-shank taps of this size class.

Installation Notes

Threading operations should be performed by a qualified machinist or maintenance professional familiar with proper tap drill sizing for 3/8-24 UNF threads. Always use appropriate cutting fluid for the workpiece material to extend tap life and improve thread quality. For blind holes, use a taper or plug tap first to start the thread before finishing with this bottoming tap. Apply steady, even pressure and back off periodically to break chips and prevent tap breakage.