Eagle Cutting Tool HT-640-B-D 6-40 Hss Bottom Tap

Product Description

The EAGLE CUTTING TOOL HT-640-B-D is a 6-40 high-speed steel (HSS) bottom tap manufactured in the USA. Bottom taps, also called plug-bottoming or bottoming taps, are ground with a minimal lead chamfer so threads can be cut to the full depth of a blind hole. The 6-40 thread designation indicates a No. 6 screw size with 40 threads per inch, a fine-pitch specification common in precision mechanical and electrical assemblies. This tap is suited for machinists, maintenance technicians, and field service professionals who need to thread or re-thread small-diameter blind holes cleanly and completely.

The HT-640-B-D is used wherever a 6-40 threaded hole must be tapped to its full depth, including instrument panels, electrical enclosures, light mechanical assemblies, and precision fixtures. The fine 40-TPI pitch makes it appropriate for thin-walled materials and applications where vibration resistance or close tolerancing is required. It is a standard production tap appropriate for both shop and field use on ferrous and non-ferrous materials.

Key Features

• Bottom tap geometry allows threading to the full depth of blind holes
• 6-40 thread form — No. 6 screw diameter, 40 threads per inch fine pitch
• High-speed steel (HSS) construction for durability across a range of workpiece materials
• USA manufactured
• Lightweight at 0.08 pounds — suitable for hand tap wrenches and small machine tap holders

Compatibility

Designed as a standard replacement or production tap for any application requiring a 6-40 UNF threaded hole tapped to full blind-hole depth.

Installation Notes

This tap is installed by a machinist or maintenance technician using a hand tap wrench or tapping head sized for the tap shank. Before tapping, ensure the correct drill size for a 6-40 thread is used and the workpiece is securely fixtured. Apply cutting fluid appropriate for the workpiece material to reduce heat and extend tap life. Back the tap off periodically to break chips and prevent binding, especially in blind holes.

Technical Specifications

• Thread Size: 6-40
• Tap Type: Bottom Tap
• Material: High-Speed Steel (HSS)
• Country of Origin: USA
• Weight: 0.08 pounds

Standard Information

• Brand: EAGLE CUTTING TOOL
• Manufacturer Part Number: HT-640-B-D