Eagle Cutting Tool HT-448-B-D 4-48 Hss Bottom Tap

Product Description

The EAGLE CUTTING TOOL HT-448-B-D is a 4-48 UNF high-speed steel bottom tap manufactured in the USA. Bottom taps are ground with a near-zero lead chamfer, typically one to two threads, allowing the cutting flutes to reach the bottom of a blind hole and produce fully formed threads along nearly the entire depth of the bore. This tap is suited for threading small-diameter holes in ferrous and non-ferrous metals, plastics, and similar materials where thread depth must extend close to the bottom of the hole. At 0.04 pounds, it is a lightweight precision tool appropriate for bench work, CNC tapping, or hand-tapping operations.

The HT-448-B-D is used in machine shops, maintenance and repair operations, and light manufacturing environments where 4-48 UNF threads are required in blind holes. The 4-48 thread form is common in instrument assembly, electronics enclosures, and precision mechanical subassemblies. This tap is appropriate for use in drill presses, CNC machining centers, or by hand with a tap wrench, depending on the application and required tolerances.

Key Features

• Bottom chamfer geometry allows threading to near-bottom of blind holes
• 4-48 UNF thread form for fine-pitch small-diameter applications
• High-speed steel (HSS) construction provides wear resistance for production and repeat use
• USA manufactured for consistent dimensional accuracy and heat treatment
• Lightweight at 0.04 pounds for easy handling and tool storage

Compatibility

Designed as a standard 4-48 UNF bottom tap for use wherever that thread form is required in blind-hole applications across metalworking and precision assembly trades.

Installation Notes

Machinists and maintenance technicians should ensure the pilot hole is drilled to the correct tap drill size for 4-48 UNF threads before tapping. Use appropriate cutting fluid for the workpiece material to extend tap life and improve thread quality. Apply steady, even torque when tapping by hand and back off periodically to break chips and prevent tap breakage in deep blind holes. Never force a tap against the bottom of a blind hole without confirming adequate depth clearance.

Technical Specifications

• Thread Size: 4-48 UNF
• Tap Type: Bottom
• Material: High-Speed Steel (HSS)
• Country of Origin: USA
• Weight: 0.04 pounds

Standard Information

• Brand: EAGLE CUTTING TOOL
• Manufacturer Part Number: HT-448-B-D