Eagle Cutting Tool HT-3125-18-T-I 5/16-18 Hss Taper Tap

Product Description

The EAGLE CUTTING TOOL HT-3125-18-T-I is a 5/16-18 high-speed steel (HSS) hand taper tap designed for cutting internal threads in metal workpieces. The taper tap features a gradual thread chamfer that eases the tool into the cut, reducing torque requirements and minimizing the chance of breakage when starting a new hole. Built from HSS, the tap holds its edge under the heat generated by hand-threading operations in steel, iron, aluminum, and similar materials. This tool is sized for the 5/16-18 Unified National Coarse (UNC) thread standard, one of the most common fastener threads used in general mechanical assemblies and repair work.

This tap is suited for maintenance, repair, and fabrication environments where 5/16-18 threaded holes need to be cut or restored by hand. Typical applications include machine shops, HVAC equipment fabrication, plumbing fixture repair, electrical enclosure work, and general industrial maintenance. The hand-drive format makes it appropriate for bench work and field repairs where a tap wrench or adjustable handle is used rather than a power driver.

Key Features

• 5/16-18 UNC thread form for one of the most widely used coarse-thread fastener sizes
• High-speed steel construction provides heat resistance and edge retention during hand-threading operations
• Taper chamfer eases entry into the workpiece and reduces starting torque
• Import-grade tool suitable for general maintenance and low-to-medium volume thread-cutting tasks
• Lightweight at 0.31 pounds, easy to handle and store in a tap-and-die set or toolbox

Compatibility

Designed for cutting 5/16-18 UNC internal threads in through-holes or deep blind holes where a taper start is required. Compatible with standard tap wrenches and adjustable tap handles sized for this shank diameter.

Installation Notes

This tap is installed by a machinist or maintenance technician using a tap wrench. Ensure the workpiece is securely fixtured before tapping. Use appropriate cutting fluid for the base material to extend tap life and produce cleaner threads. Back the tap off periodically to break chips and prevent binding. Do not apply excessive force — HSS taps can fracture if forced through an undersized pilot hole or driven without adequate lubrication.

Technical Specifications

• Thread Size: 5/16-18 UNC
• Thread Type: Unified National Coarse (UNC)
• Tap Style: Hand Taper
• Material: High-Speed Steel (HSS)
• Weight: 0.31 pounds

Standard Information

• Brand: EAGLE CUTTING TOOL
• Manufacturer Part Number: HT-3125-18-T-I