Osg 1206408 Spiral Point Tap 4-40 Unc Hss Ticn

Product Description

The OSG 1206408 is a spiral point plug tap designed for cutting 4-40 UNC internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel with a titanium carbonitride (TiCN) coating, it delivers improved wear resistance and reduced friction compared to uncoated HSS taps. The plug chamfer distributes cutting load across the lead threads and is well suited for through-hole tapping applications. With 2 flutes and a right-hand thread direction, it pushes chips ahead of the tap and out of the hole, keeping the cutting zone clear. Overall length is 1.875 inches with a thread length of 0.319 inches and a shank diameter of 0.141 inches. This tap is used by machinists, tool and die makers, and maintenance technicians in production and repair environments.

The OSG 1206408 is rated for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. The H2 thread limit designation means the tap produces threads toward the high end of tolerance, making it compatible with both 2B and 3B class-of-fit specifications. It is suited to through-hole applications in light production runs, job shop work, and field repair tasks where a reliable, coated HSS tap is required without the cost of carbide tooling.

Key Features

• Spiral point geometry pushes chips forward through the hole, reducing clogging in through-hole applications
• TiCN coating improves surface hardness and reduces built-up edge on aluminum and steel workpieces
• High-speed steel construction provides toughness and resistance to chipping under interrupted cuts
• H2 thread limit supports both 2B and 3B class-of-fit thread requirements
• Plug chamfer with 2 flutes balances cutting load and is suitable for hand or machine tapping
• Right-hand thread direction; no coolant-through feature required for standard applications

Compatibility

Designed for through-hole tapping of 4-40 UNC threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces. Compatible with 2B and 3B class-of-fit thread standards per the H2 thread limit.

Installation Notes

A licensed machinist or qualified maintenance technician should select the correct tap drill size for 4-40 UNC threads before use. Power down and lock out all equipment before performing any tapping operation on installed machinery. Use a suitable cutting fluid or tapping compound for the workpiece material to extend tool life and improve thread finish. Do not exceed the recommended speed range for the tap size and material combination, and never reverse a spiral point tap under power to back it out of a blind hole.