Eagle Cutting Tool HT-21250-8-B-I Hss Hand Bottom Tap

Product Description

The EAGLE CUTTING TOOL HT-21250-8-B-I is a high-speed steel (HSS) hand bottom tap designed for threading operations that require thread cutting to the bottom of a blind hole. With a 2-1/8 inch nominal diameter and 8 threads per inch (TPI), this tap handles large-diameter threading tasks common in heavy fabrication, industrial maintenance, and mechanical assembly work. The bottom chamfer geometry allows threads to be cut as close to the base of a blind hole as possible, making it the correct choice when a plug or taper tap cannot complete the job. Machinists, pipefitters, and maintenance technicians install this tap by hand using a standard tap wrench.

This tap is suited for applications in industrial and commercial environments where large-diameter internal threads are required in steel, iron, or similar materials. Typical use cases include threading bores in heavy equipment components, machine frames, fixtures, and structural assemblies. The 8 TPI coarse thread pitch is standard for this diameter range and is widely used in general mechanical and structural applications. The hand tap designation means it is driven manually rather than by a machine tapping head, giving the operator direct feel and control over the threading process.

Key Features

• 2-1/8 inch nominal diameter with 8 TPI coarse thread pitch for large-diameter blind-hole threading
• Bottom chamfer allows thread cutting to the base of blind holes where plug or taper taps cannot reach
• High-speed steel (HSS) construction provides hardness and wear resistance for threading ferrous materials
• Hand tap design allows controlled manual operation with a standard tap wrench
• Import-grade tooling suited for production, maintenance, and repair applications

Compatibility

Designed as a standard hand bottom tap for use in any application requiring 2-1/8 inch - 8 TPI internal threads, compatible with standard tap wrenches sized for large-diameter taps.

Installation Notes

This tap is installed by a machinist or maintenance technician using a tap wrench sized appropriately for the square drive shank. Always drill the correct tap drill size for a 2-1/8 inch - 8 TPI thread before beginning the tapping operation and ensure the workpiece is securely fixtured. Apply cutting fluid throughout the threading process to reduce heat and extend tool life. Back off the tap periodically to break chips and prevent binding, particularly in deep blind holes.

Technical Specifications

• Nominal Diameter: 2-1/8 inches
• Thread Pitch: 8 TPI
• Tap Type: Hand Bottom Tap
• Material: High-Speed Steel (HSS)
• Weight: 6.3 pounds

Standard Information

• Brand: EAGLE CUTTING TOOL
• Manufacturer Part Number: HT-21250-8-B-I