Osg 1405008008 Thread Forming Tap 1/4-28 Unf Ticn Coated

Product Description

The OSG 1405008008 is a thread forming tap in the EXOTAP NRT Series designed for cold-forming internal threads in ductile metals without cutting or producing chips. Built from powdered metal high-speed steel and coated with TiCN for improved wear resistance and lubricity, this tap is engineered for demanding production and maintenance threading applications. It carries a 1/4-28 UNF thread specification with a modified bottoming chamfer of 2 to 2.5 threads, allowing it to thread close to the bottom of a blind hole. The H4 thread limit provides a controlled fit class suitable for close-tolerance fastener applications. Overall length is 2.5 inches with a thread length of 0.5945 inches and a tapping depth of 0.9960 inches.

This tap is suited for blind hole threading operations across a range of ferrous and non-ferrous materials including alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. It is commonly used in machining centers, CNC tapping operations, and manual tap work where chip evacuation is a concern or where thread strength requirements favor a formed thread over a cut thread. The right-hand thread direction matches standard UNF fastener orientation. Machinists, tool-and-die makers, and maintenance technicians working in manufacturing, aerospace, and general industrial environments will find this tap appropriate for precision blind hole work.

Key Features

• Thread forming design eliminates chips, reducing risk of chip packing in blind holes
• Powdered metal high-speed steel construction provides uniform carbide distribution for extended tool life
• TiCN coating (finish code V) improves surface hardness and reduces friction during tapping
• Modified bottoming chamfer (2 to 2.5P) enables threading close to blind hole bottom
• H4 thread limit for controlled, close-tolerance UNF thread fitment
• Right-hand thread direction, compatible with standard 1/4-28 UNF fastener systems

Compatibility

Designed for 1/4-28 UNF blind hole threading applications in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P, M, and N apply.

Installation Notes

Thread forming taps require adequate lubrication or cutting fluid matched to the workpiece material to prevent galling, particularly in stainless steel and hardened steel. Ensure the tap driver and machine spindle are properly aligned before tapping to avoid tap breakage. Power down or de-energize any machine tool before changing taps or adjusting tooling. Use a tap holder with appropriate torque limiting to avoid over-torque in harder materials.