Osg 1400102201 Thread Forming Tap 2-56 Unc Bottoming Cobalt

Product Description

The OSG 1400102201 is a thread forming tap designed for creating internal 2-56 UNC threads in blind holes without cutting chips. Unlike cutting taps, this bottoming-style forming tap displaces material to produce stronger, work-hardened threads. Built from cobalt high-speed steel with a steam oxide coating, it handles the heat and pressure of thread forming in a range of ferrous and non-ferrous materials. The H2 thread limit ensures tight dimensional control for Class 3B fits. At 1.75 inches overall length with a 0.437-inch thread length, it fits standard tapping chucks and hand tap wrenches used by machinists and toolroom technicians.

This tap is suited for production and maintenance tapping operations in alloy steel, carbon steel, die steel, hardened steel, aluminum, and stainless steel workpieces. The bottoming chamfer, with 1 to 1.5 chamfered threads, allows threading close to the bottom of a blind hole, making it a practical choice when thread runout must be minimized. It is commonly used in aerospace, automotive, and general metalworking applications where fine 2-56 UNC threads are required in tight tolerances.

Key Features

• Thread forming design eliminates chips, reducing tap breakage risk in blind holes
• Cobalt high-speed steel construction improves heat and wear resistance over standard HSS
• Steam oxide coating reduces friction and improves lubrication retention during tapping
• Bottoming chamfer (1 to 1.5 threads) enables threading close to blind hole bottom
• H2 thread limit supports Class 3B fit requirements
• Right-hand thread direction, compatible with standard tapping equipment

Compatibility

Designed for blind hole thread forming in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. Part of the OSG HY-PRO NRT series, Series 14001.

Installation Notes

Thread forming taps require proper cutting fluid or tapping compound matched to the workpiece material — dry tapping is not recommended. Ensure the tap is aligned perpendicular to the workpiece surface before engagement to avoid cross-threading or tap breakage. Use a torque-limiting tapping chuck when running on machine tools. Confirm correct drill size for the thread form before tapping, as thread forming taps require a larger pilot hole than cutting taps for the same thread size.