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

Product Description

The EAGLE CUTTING TOOL HT-3125-18-T-D is a 5/16-18 high-speed steel (HSS) hand taper tap manufactured in the USA. Taper taps are used to start a thread in a hole, providing gradual cutting action over the first 8 to 10 leading threads to reduce torque and guide the tap squarely into the work. This tap cuts a 5/16-inch major diameter thread at 18 threads per inch (UNC coarse pitch). It is a hand tap intended for manual tapping operations and light machine tapping. The HSS construction provides good wear resistance and toughness across a range of workpiece materials including mild steel, aluminum, and similar metals.

This tap is suited for maintenance, repair, and fabrication work where 5/16-18 UNC threaded holes are required. Typical applications include general metalworking, machine shops, HVAC equipment assembly, plumbing fixture fabrication, and field repair work. The taper chamfer makes it the preferred starting tap when threading blind or through holes from scratch. It is commonly used by machinists, millwrights, pipefitters, and maintenance technicians who need to cut or restore internal threads by hand or with a tapping fixture.

Key Features

• 5/16-18 UNC thread form for coarse-pitch internal threading
• Taper chamfer (8-10 leading threads) for easy thread starting and reduced cutting torque
• High-speed steel (HSS) construction for durability across common workpiece materials
• USA manufactured for consistent dimensional accuracy and thread form compliance
• Hand tap design suitable for manual tapping wrenches and tapping fixtures

Compatibility

Designed for use in any application requiring a 5/16-18 UNC internal thread. Compatible with standard tap wrenches and T-handle tap holders sized for hand taps in this diameter range.

Installation Notes

Secure the workpiece firmly before tapping. Use the appropriate cutting fluid or tapping compound for the material being threaded to extend tap life and improve thread finish. Back the tap off a partial turn periodically to break chips and prevent binding. Inspect the tap for wear or damage before each use, as a damaged tap can strip threads or break in the hole.

Technical Specifications

• Thread Size: 5/16-18 UNC
• Tap Type: Hand Taper Tap
• Material: High-Speed Steel (HSS)
• Country of Origin: USA
• Weight: 0.06 pounds
• Minimum Order Quantity: 1

Standard Information

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