Import BDNA-20696 Tap Set 1-8 Unc Hss 3 Piece

Product Description

The IMPORT BDNA-20696 is a three-piece high-speed steel tap set designed for cutting 1-8 UNC internal threads. The set includes bottoming, plug, and taper chamfer taps, providing the full sequence needed to thread a hole from start to finish. Each tap features four flutes for efficient chip evacuation and a gold oxide finish that provides light lubricity and corrosion resistance during use. At 5.125 inches overall length, these taps are suited for standard drill presses, tapping arms, and hand tap wrenches. Machinists, maintenance mechanics, and fabrication professionals reach for this set when threading large-diameter, coarse-pitch holes in steel, iron, and similar materials.

This tap set is used in general metalworking, industrial maintenance, and fabrication shops where 1-8 UNC threads are required. The 1-8 UNC designation indicates a 1-inch nominal diameter with 8 threads per inch, a common specification for heavy fasteners, structural bolts, and large machine components. The H4 thread limit makes this set appropriate for threading materials where a controlled fit with standard UNC fasteners is needed. The three-chamfer configuration supports progressive thread cutting, starting with the taper tap for initial engagement, the plug tap for intermediate threading, and the bottoming tap for threading to the bottom of a blind hole.

Key Features

• Three-piece set includes taper, plug, and bottoming chamfer taps for complete threading sequence
• 1-8 UNC thread form with H4 thread limit for controlled fit
• High-speed steel construction for durability in ferrous and non-ferrous metals
• Four-flute design promotes chip clearance and cutting efficiency
• Gold oxide finish provides light lubricity and surface protection
• 5.125 inches overall length fits standard tap wrenches and tapping equipment

Compatibility

Designed for use in any application requiring 1-8 UNC internal threads, compatible with standard 1-inch UNC bolts and fasteners per the Unified National Coarse thread standard.

Installation Notes

Tap installation should be performed by a qualified machinist or maintenance mechanic. Always secure the workpiece firmly before tapping and use an appropriate cutting fluid to extend tap life and improve thread quality. Begin with the taper tap to start the thread, follow with the plug tap, and finish with the bottoming tap when threading to the bottom of a blind hole. Inspect taps for wear or chipping before each use and never force a tap, as breakage in a blind hole can be difficult to recover.