Osg 1720601 Spiral Flute Tap 1/2-13 Unc 3 Flute 2B

Product Description

The OSG 1720601 is a spiral flute tap designed for threading 1/2-13 UNC holes in difficult-to-machine materials. It features a modified bottoming chamfer, 3 right-hand spiral flutes with a 10-degree helix angle, and a steam oxide coating. The H5 thread limit and 2B class of fit make it suitable for standard tolerance threaded holes. Constructed from powdered metal, this tap is built to handle the demands of production threading where chip evacuation in blind holes is a priority. It is used by machinists and tool-and-die professionals working on CNC machining centers and manual tapping operations.

The OSG 1720601 is specifically engineered for threading stainless steel, hardened steel, titanium, and high-nickel alloys — materials that generate stringy chips and require the upward chip-ejection action of a spiral flute design. The modified bottoming chamfer allows threading closer to the bottom of a blind hole than a standard taper or plug tap, making it well-suited for close-tolerance assemblies and repair work where thread depth is critical. It belongs to OSG Series 313NI, a line targeted at challenging workpiece materials in aerospace, medical, and industrial manufacturing applications.

Key Features

• 1/2-13 UNC thread form, right-hand thread direction
• 3 right-hand spiral flutes with 10-degree helix angle for upward chip ejection in blind holes
• Modified bottoming chamfer for threading close to the bottom of blind holes
• Powdered metal construction with steam oxide coating for lubricity and wear resistance
• H5 thread limit, 2B class of fit for standard tolerance threaded holes
• Rated for stainless steel, hardened steel, titanium, and high-nickel alloys

Compatibility

Designed for use in stainless steel, hardened steel, titanium, and high-nickel alloy workpieces. Part of OSG Series 313NI. Compatible with standard 1/2-inch tap holders and floating tap chucks accepting a 0.275-inch square drive shank.

Installation Notes

This tap is installed by a machinist or toolroom technician using a CNC machining center, drill press, or manual tapping fixture. Ensure the spindle is fully stopped and the workpiece is securely fixtured before tool changes. Use a cutting fluid or tapping compound rated for the workpiece material — this is especially important when threading stainless steel or titanium to prevent galling and tap breakage. Do not exceed the recommended feed rate for the thread pitch; forcing a spiral flute tap into a hole without proper chip evacuation will result in tap failure.