Eagle Cutting Tool SP-3125-18-P-I 5/16-18 Spiral Point Plug Tap

Product Description

The EAGLE CUTTING TOOL SP-3125-18-P-I is a 5/16-18 high-speed steel (HSS) spiral point plug tap designed for threading through-holes in metalworking applications. The spiral point geometry pushes chips forward ahead of the cutting edge, reducing clogging and allowing smooth, consistent thread formation at production speeds. Built to plug tap standards, it starts threading from a chamfered lead and is suited for use with standard tapping machines, CNC machining centers, or hand tap wrenches. Machinists, maintenance techs, and tool-and-die professionals reach for this tap when cutting unified coarse (UNC) internal threads in steel, aluminum, and similar materials.

This tap is intended for through-hole threading operations where chip evacuation in a forward direction is acceptable. The 5/16-18 UNC thread form is one of the most common fastener sizes encountered in general manufacturing, maintenance, and repair environments. It is appropriate for use in ferrous and non-ferrous workpiece materials and fits standard tap holders sized for 5/16-inch shank tooling. The import designation indicates value-tier sourcing suited for general-purpose shop use rather than high-volume production tooling programs.

Key Features

• 5/16-18 UNC thread form for one of the most widely used fastener sizes in general metalwork
• Spiral point geometry drives chips forward, reducing tap breakage and improving hole finish in through-hole applications
• High-speed steel (HSS) construction provides adequate hardness and wear resistance for common shop materials
• Plug chamfer lead (3-5 threads) allows easy thread starting without requiring a taper tap
• Lightweight at 0.1 pounds, compatible with standard tap handles and machine tap holders

Compatibility

Designed as a general-purpose replacement or stock tap for standard 5/16-18 UNC through-hole threading applications across common shop and maintenance environments.

Installation Notes

This tap is installed and operated by qualified machinists or maintenance technicians using a tap wrench, tapping head, or CNC rigid-tapping setup. Always use the correct tap drill size for a 5/16-18 thread before tapping, and apply appropriate cutting fluid to extend tool life and improve thread quality. Secure the workpiece firmly before beginning the tapping operation. Reverse the tap periodically when hand-tapping to break chips and prevent binding.

Technical Specifications

• Thread Size: 5/16-18 UNC
• Tap Type: Spiral Point Plug Tap
• Material: High-Speed Steel (HSS)
• Weight: 0.1 pounds
• Minimum Order Quantity: 1

Standard Information

• Brand: EAGLE CUTTING TOOL
• Manufacturer Part Number: SP-3125-18-P-I