Eagle Cutting Tool HT-540-B-I 5-40 Hss Hand Bottom Tap

Product Description

The EAGLE CUTTING TOOL HT-540-B-I is a 5-40 UNC high-speed steel (HSS) hand bottom tap designed for cutting internal threads to the bottom of blind holes. The bottom tap geometry features minimal lead threads, allowing it to thread deeper into a hole than taper or plug taps. At 0.31 pounds, this is a lightweight, single-piece cutting tool suited for bench work and field repairs. Machinists, maintenance technicians, and tool-and-die professionals install this tap by hand using a standard tap wrench or T-handle driver.

This tap is used in applications where a 5-40 UNC thread must be cut in a blind hole and full thread depth is required close to the hole bottom. Common scenarios include tapping small fastener holes in instrument housings, electronic enclosures, thin-gauge metal brackets, and precision assemblies. The 5-40 thread designation indicates a No. 5 screw size with 40 threads per inch, a fine pitch frequently found in small mechanical and electrical hardware.

Key Features

• Bottom tap style allows threading to the base of blind holes with minimal unthreaded runout
• High-speed steel (HSS) construction provides hardness and wear resistance across a range of base metals including mild steel, aluminum, and brass
• 5-40 UNC thread form for No. 5 screw diameter at 40 threads per inch
• Lightweight at 0.31 pounds for easy single-hand use with a tap wrench
• Import-grade tooling suitable for general maintenance, repair, and low-to-medium volume production work

Compatibility

Designed as a standard hand tap for use in any application requiring a 5-40 UNC internal thread, compatible with tap wrenches and T-handle drivers sized for small-shank taps.

Installation Notes

Secure the workpiece firmly before tapping. Apply cutting fluid or tapping oil to the tap and hole to reduce heat and extend tool life. Advance the tap slowly with a tap wrench, backing off a half turn periodically to break chips and prevent binding. Inspect the tap for wear or damage before each use, as a broken tap in a blind hole can be difficult to remove.

Technical Specifications

• Thread Size: 5-40 UNC
• Tap Type: Hand Bottom Tap
• Material: High-Speed Steel (HSS)
• Weight: 0.31 pounds

Standard Information

• Brand: EAGLE CUTTING TOOL
• Manufacturer Part Number: HT-540-B-I