Osg 1400102605 Thread Forming Tap 2-56 Unc Cobalt Tin

Product Description

The OSG 1400102605 is a thread forming tap designed for cold-forming internal threads in metal without cutting or producing chips. Part of the HY-PRO NRT series, it produces a 2-56 UNC right-hand thread with a modified bottoming chamfer of 2 to 2.5 threads. The tap is manufactured from cobalt high-speed steel and finished with a titanium nitride (TiN) coating to extend tool life and reduce friction. Overall length is 1.75 inches with a thread length of 0.437 inches and a shank diameter of 0.141 inches. It carries a Class 2B fit with a Thread Limit of H3. Licensed machinists, tool-and-die makers, and precision machine operators are the typical users.

This tap is suited for blind hole threading applications in a wide range of metallic workpiece materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The modified bottoming chamfer allows threading closer to the bottom of a blind hole than a standard plug chamfer, making it useful where thread engagement depth is critical and hole depth is limited. It is appropriate for both production and repair threading operations in machining centers, drill presses, and tapping machines.

Key Features

• Thread forming (cold-forming) design eliminates chips for cleaner blind hole threading
• Cobalt high-speed steel construction provides heat and wear resistance in tough materials
• TiN coating reduces friction, extends tool life, and improves thread surface finish
• Modified bottoming chamfer (2 to 2.5 threads) enables threading close to the bottom of blind holes
• H3 thread limit with Class 2B fit for consistent, accurate thread production
• Right-hand thread direction, no coolant-through requirement

Compatibility

Designed for use in blind hole threading of alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces requiring a 2-56 UNC internal thread with a Class 2B fit.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which is larger than a standard cut tap drill — consult published forming tap drill charts for the correct pilot hole diameter before use. Secure the tap in a rigid tapping holder or floating tap adapter appropriate for the machine type. Apply a suitable tapping fluid or cutting oil rated for the workpiece material to reduce forming torque and protect the tool. Always back the tap out completely before removing the workpiece to avoid tap breakage in the blind hole.