Osg 1400144901 Thread Forming Tap 1/2-20 Unf Cobalt

Product Description

The OSG 1400144901 is a thread forming tap designed for cold-forming internal threads in ductile metals without cutting or producing chips. Part of the HY-PRO NRT series, it produces a 1/2-20 UNF right-hand thread with a modified bottoming chamfer of 2 to 2.5 threads, allowing threading close to the bottom of a blind hole. The tap is manufactured from cobalt high-speed steel and finished with a steam oxide coating that provides lubricity and helps resist galling during the forming process. Overall length is 3.375 inches with a shank diameter of 0.367 inches. Class of fit is 2B with a thread limit of H8, making it suitable for close-tolerance work in production and maintenance environments.

This tap is rated for use in blind hole threading applications across a range of ferrous and non-ferrous materials including alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. The modified bottoming chamfer makes it well suited for shallow through-to-bottom blind hole requirements where a standard bottoming or plug tap may not reach the required depth. Machinists, tool-and-die makers, and maintenance technicians working in production shops, fabrication facilities, and MRO environments will find this tap applicable across a broad range of workpiece materials.

Key Features

• Thread size 1/2-20 UNF right-hand thread, class of fit 2B, thread limit H8
• Modified bottoming chamfer with 2 to 2.5 chamfered threads for near-bottom blind hole access
• Cobalt high-speed steel construction for improved heat and wear resistance in tough alloys
• Steam oxide coating reduces friction and galling during cold-forming operations
• Thread forming design produces no chips, eliminating chip-clearing concerns in blind holes
• Compatible with material application codes P and N covering steels and non-ferrous materials

Compatibility

Rated for use in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Intended for blind hole threading applications requiring a 1/2-20 UNF internal thread to class 2B fit.

Installation Notes

Thread forming taps require adequate lubrication or cutting fluid appropriate to the workpiece material; consult tooling guidelines for the specific material being tapped. Ensure the pilot hole diameter is sized correctly for a thread forming tap, as the required hole diameter differs from that used for a cutting tap of the same thread size. Secure the workpiece and use a rigid tapping setup or a tapping head to maintain axial alignment and avoid tap breakage. Power down or de-energize any machine spindle before changing or inspecting the tap.