Osg 1301900503 Spiral Flute Tap 10-24 Unc Nitride Hss

Product Description

The OSG 1301900503 is a spiral flute tap designed for cutting 10-24 UNC internal threads in a modified bottoming configuration. Built from vanadium high-speed steel with a nitride coating, this tap delivers extended tool life and reduced friction during the tapping cycle. The 50-degree helix angle and three right-hand spiral flutes eject chips upward, making it well suited for blind-hole applications where chip buildup causes thread damage or tap breakage. It holds a 2B class of fit with an H3 thread limit, meeting standard tolerance requirements for most fastener applications. Overall length is 2.5 inches with a 0.875-inch thread length. A licensed machinist or tool-and-die professional installs this tap in a tapping fixture, CNC machine, or hand tap holder.

This tap is optimized for use in aluminum and similarly machinable non-ferrous materials. The modified bottoming chamfer allows threading closer to the bottom of a blind hole than a standard plug or taper chamfer permits, making it a practical choice for tight-clearance assemblies in light manufacturing, HVAC equipment fabrication, and mechanical sub-assembly work. The nitride surface treatment improves lubricity and resists built-up edge when cutting aluminum. Series 13019 is OSG's catalog designation for this tap family. Package quantity is one tap per unit.

Key Features

• Three right-hand spiral flutes with a 50-degree helix angle for efficient upward chip ejection in blind holes
• Modified bottoming chamfer for threading close to the base of a blind hole
• Vanadium high-speed steel construction for wear resistance in production tapping
• Nitride coating reduces friction and improves performance in aluminum
• 2B class of fit with H3 thread limit meets standard UNC tolerance requirements
• Coolant-through design is not required — standard through-coolant is not supported

Compatibility

Designed for cutting 10-24 UNC right-hand threads in aluminum and comparable machinable materials; compatible with standard straight-shank tap holders and CNC tapping chucks sized for a 0.255-inch shank diameter.

Installation Notes

This tap is installed by a machinist using a tapping fixture, rigid tap holder, or floating tap chuck in a drill press or CNC machining center. Power down and secure the workpiece before tool changes. Use appropriate cutting fluid for the workpiece material to extend tap life and maintain thread quality. Inspect the tap for chipping or wear before each use — a worn or chipped tap produces out-of-tolerance threads and risks breakage in the hole.