Import BDNA-20694 Tap Set 7/8-9 Unc 4 Flute Hss

Product Description

The IMPORT BDNA-20694 is a 3-piece tap set designed for cutting 7/8-9 UNC internal threads in metal workpieces. The set includes bottoming, plug, and taper chamfer taps, allowing machinists and trade professionals to start, advance, and finish threads in a single progression. All three taps are ground from high-speed steel (HSS) with a gold oxide finish and feature 4 flutes for effective chip evacuation. Overall length is 4-11/16 inches. The H4 thread limit provides the relief needed for threading harder materials and plated fastener applications.

This tap set is suited for general metalworking, maintenance, repair, and fabrication environments where 7/8-9 UNC threads are required. The three-chamfer combination makes the set practical for both through-hole and blind-hole applications. Typical users include machinists, millwrights, pipefitters, and maintenance mechanics working in industrial and commercial settings. The gold oxide coating provides a degree of lubricity and corrosion resistance during cutting operations.

Key Features

• 3-piece set includes bottoming, plug, and taper chamfer taps for complete thread progression
• High-speed steel construction for durability across a range of ferrous and non-ferrous materials
• 4-flute design promotes efficient chip removal and cleaner thread form
• H4 thread limit suitable for threading harder alloys and accommodating plated components
• Gold oxide finish adds surface lubricity and light corrosion protection
• 4-11/16 inches overall length fits standard tap handles and machine setups

Compatibility

Designed for cutting 7/8-9 UNC internal threads per Unified National Coarse thread standards. Fits standard tap wrenches and machine tap holders sized for 7/8-9 taps.

Installation Notes

Tapping operations should be performed by qualified machinists or trade professionals familiar with thread cutting procedures. Always secure the workpiece firmly before beginning and use an appropriate cutting fluid to reduce heat and extend tap life. Back the tap out periodically to break and clear chips, especially in blind holes. Refer to the applicable thread standard and shop procedures for proper drill size selection prior to tapping.