Osg 1400105600 Thread Forming Tap 4-40 Unc Cobalt

Product Description

The OSG 1400105600 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting. Sized at 4-40 UNC with a modified bottoming chamfer, this tap displaces material rather than removing chips, producing stronger threads with better surface finish in ductile metals. It is manufactured from cobalt high-speed steel with a bright finish and carries a H6 thread limit. At 1.875 inches overall length and a shank diameter of 0.141 inches, it is suited for precision tapping operations in small-diameter blind holes. Machinists and tool-and-die professionals install this tap in CNC machining centers, drill presses, and manual tapping setups.

This tap is engineered for blind hole threading applications in a wide range of metals. Supported material applications include alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel, corresponding to material application codes P and N. The modified bottoming chamfer with 2 to 2.5 chamfered threads allows the tap to thread close to the bottom of a blind hole, making it appropriate for tight-tolerance assemblies where thread depth is critical. It is a right-hand tap producing 40 threads per inch at a 4-40 UNC pitch.

Key Features

• Thread forming design displaces material rather than cutting, producing stronger threads with no chips
• Modified bottoming chamfer (2 to 2.5 chamfered threads) for threading close to the bottom of blind holes
• Cobalt high-speed steel construction for improved heat and wear resistance in tough materials
• H6 thread limit for consistent tolerance control in precision applications
• Bright finish with no coolant-through requirement, suitable for standard lubricated tapping
• Right-hand thread direction, 40 TPI, compatible with standard 4-40 UNC thread gages and fasteners

Compatibility

Designed for blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces requiring 4-40 UNC internal threads.

Installation Notes

Thread forming taps must be used with an appropriate tapping lubricant or cutting fluid matched to the workpiece material. Power down or disable the spindle before loading or removing the tap from the holder. Use a properly sized tap holder with controlled axial float to avoid tap breakage in small-diameter applications. Follow shop standards and machine manufacturer guidelines for spindle speed and feed rate when tapping small-diameter threads in hard materials.