Osg 1400105205 Thread Forming Tap 4-40 Unc Cobalt Tin

Product Description

The OSG 1400105205 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting chips. It produces 4-40 UNC right-hand threads in blind hole applications using a modified bottoming chamfer with 2 to 2.5 chamfered threads. Manufactured from cobalt high-speed steel and coated with titanium nitride (TiN), it is built for extended tool life in demanding threading operations. The H2 thread limit provides consistent dimensional control. With an overall length of 1.875 inches and a tapping depth of 0.559 inches, it fits standard tap holders for small-fastener work in machining and fabrication environments.

This tap is suited for threading blind holes in a broad range of metallic workpiece materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The thread forming method displaces material rather than cutting it, resulting in stronger threads with no chip evacuation concerns. It is commonly used in precision machining, toolroom work, CNC tapping operations, and general metalworking where 4-40 UNC fastener holes are required at tight tolerances.

Key Features

• Thread forming (chipless) design eliminates chip packing in blind holes
• Cobalt HSS construction for heat and wear resistance in tough alloys
• TiN coating reduces friction and extends tool life across multiple materials
• Modified bottoming chamfer (2 to 2.5P) allows threading close to the bottom of blind holes
• H2 thread limit for consistent, close-tolerance thread production
• Right-hand thread direction, compatible with standard tap drivers and CNC toolholders

Compatibility

Designed for use in blind hole threading of 4-40 UNC threads in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N apply.

Installation Notes

This tap should be installed by a machinist or toolroom technician familiar with thread forming operations. Ensure the correct pilot hole diameter for thread forming is used, as it differs from a cut-tap pilot hole. Secure the workpiece and use a tap holder with appropriate torque control to avoid tap breakage in small diameters. Apply cutting fluid or tapping compound appropriate for the workpiece material before and during the tapping operation.