Osg 1749908 Spiral Flute Tap 9/16-12 Unc 3 Flute Ticn Hss

Product Description

The OSG 1749908 is a spiral flute tap designed for cutting 9/16-12 UNC internal threads in a range of ferrous materials. Built from vanadium high-speed steel and finished with a TICN (titanium carbonitride) coating, it delivers improved wear resistance and lubricity compared to uncoated HSS taps. The modified bottoming chamfer allows threading closer to the bottom of blind holes. With a 45-degree helix angle and right-hand spiral flutes, the tool evacuates chips upward out of the hole, reducing the risk of chip packing in deep or interrupted cuts. It carries a 3B class of fit and H3 thread limit for consistent tolerance control. Machinists and tool-and-die professionals are the primary users.

This tap is suited for production and maintenance threading operations in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces. The modified bottoming chamfer makes it a practical choice when full thread depth close to a blind hole floor is required. The TICN coating adds thermal and abrasion resistance, extending tool life in higher-volume runs on harder materials. It is sized for use in standard 9/16-12 UNC tapping heads, tap holders, or hand-tapping setups where a spiral flute geometry is preferred over a straight flute or spiral point design.

Key Features

• 9/16-12 UNC thread form with right-hand direction and 3B class of fit
• 45-degree helix angle spiral flutes for upward chip evacuation in blind holes
• Modified bottoming chamfer for threading near the bottom of blind bores
• TICN coating improves wear resistance and reduces friction on ferrous materials
• Vanadium high-speed steel construction for toughness across a range of steel types
• H3 thread limit for controlled tolerance in standard production fitting

Compatibility

Rated for use in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. Part of OSG Series 303.

Installation Notes

Install and remove this tap using a properly sized tap wrench, tapping head, or CNC rigid-tapping holder rated for the shank diameter. Ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct tap drill diameter for 9/16-12 UNC before tapping. Apply an appropriate cutting fluid or tapping compound for the workpiece material, particularly when threading stainless steel. Inspect the tap for wear or chipping before each use and replace if thread form quality degrades.