Osg 1302000501 Spiral Flute Tap 1/4-20 Unc Hss Oxide

Product Description

The OSG 1302000501 is a spiral flute tap designed for cutting 1/4-20 UNC internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel (HSS) with a steam oxide finish, this tap runs a right-hand spiral flute at a 45-degree helix angle, which helps evacuate chips up and out of the hole during through-hole and blind-hole tapping operations. The plug chamfer provides a gradual thread lead-in and distributes cutting forces across several teeth. Class 3B fit tolerance and H3 thread limit make it suitable for close-tolerance threaded assemblies where dimensional consistency is critical. Overall length is 2.5 inches and the part weighs approximately 0.03 pounds.

This tap is suited for use in machine tapping and hand tapping operations across production and maintenance environments. It is designed to cut threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The spiral flute geometry performs well in both through-hole and short blind-hole applications where chip clearance is a consideration. It fits standard 1/4-inch tap holders and collet-style tooling common in CNC machining centers, drill presses, and tapping heads.

Key Features

• 1/4-20 UNC thread form, Class 3B fit, H3 thread limit for close-tolerance threading
• 45-degree right-hand spiral flute promotes upward chip evacuation during tapping
• Plug chamfer distributes cutting load and eases thread engagement
• High-speed steel construction with steam oxide coating for wear resistance and lubricity
• Right-hand thread direction compatible with standard tapping setups
• Rated for aluminum, cast iron, and carbon steel applications in a single tool

Compatibility

Designed for use in standard 1/4-inch tap holders as an OEM-style spiral flute tap for 1/4-20 UNC threading in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. Part of OSG Series 13020.

Installation Notes

Installation is performed by machinists or maintenance technicians using standard tapping equipment. Always apply appropriate cutting fluid or tapping compound for the workpiece material before starting the tap. Ensure the tap is aligned perpendicular to the workpiece surface to avoid thread damage or tap breakage. Reverse the tap periodically during hand tapping to break and clear chips, and never force a tap against bottoming resistance in a blind hole.