Osg 1406508 Spiral Flute Tap 4-40 Unc Bottoming Hss Ticn

Product Description

The OSG 1406508 is a spiral flute tap designed for cutting 4-40 UNC internal threads in a bottoming chamfer configuration. It is manufactured from high-speed steel (HSS) with a titanium carbonitride (TiCN) coating that increases surface hardness and reduces friction during cutting. The tap features two right-hand flutes with a 50-degree helix angle, which helps evacuate chips upward out of the hole — a critical advantage in blind-hole tapping applications. Overall length is 1.875 inches, and the thread limit is H2, suitable for 2B and 3B class-of-fit tolerances. This tool is used by machinists and maintenance technicians working on precision threading operations.

The OSG 1406508 is suited for tapping blind holes in a range of materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The bottoming chamfer allows threads to be cut close to the bottom of a blind hole, making it appropriate for applications where full thread depth near the base of the hole is required. The 50-degree helix angle promotes smooth chip flow in these confined conditions. Thread length is 0.326 inches, neck length is 0.535 inches, and shank diameter is 0.141 inches.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• 50-degree right-hand spiral flute for efficient upward chip evacuation
• TiCN coating improves wear resistance and extends tool life in ferrous and non-ferrous materials
• H2 thread limit for 2B and 3B class-of-fit tolerances
• High-speed steel construction provides toughness across a broad range of workpiece materials
• Coolant-through design is not required, simplifying setup in standard tapping operations

Compatibility

Designed for cutting 4-40 UNC internal threads with a bottoming chamfer in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces.

Installation Notes

This tap should be installed in a tapping chuck or CNC rigid tapping holder rated for the shank diameter. Ensure the workpiece is securely fixtured and the spindle is properly aligned before beginning the tapping cycle. Apply a suitable cutting fluid or tapping compound for the workpiece material to reduce heat and extend tool life. Follow standard machine shop practices for speed and feed selection based on material hardness and hole depth.