Osg 1400143705 Thread Forming Tap 1/2-13 Unc Plug Cobalt

Product Description

The OSG 1400143705 is a thread forming tap designed for cold-forming internal threads without cutting or chip generation. Part of the HY-PRO NRT series, it produces a 1/2-13 UNC thread form using a plug chamfer with 4 to 4.5 chamfered threads. The tap is manufactured from cobalt high-speed steel and finished with a titanium nitride (TiN) coating to extend tool life under demanding conditions. It carries a class of fit 3B with a thread limit of H5, making it suitable for close-tolerance work. Overall length is 3.375 inches with a shank diameter of 0.367 inches. Machinists, tool-and-die makers, and maintenance technicians install this tap in production and repair applications.

This tap is rated for through-hole threading in a range of ferrous and non-ferrous materials including alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. The thread forming process displaces material rather than removing it, resulting in stronger threads with better surface finish compared to cut taps. Coolant-through is not available on this tool, so flood or brush-applied cutting fluid is recommended for optimal performance and tool longevity. It is well suited for CNC machining centers, drill presses, and manual tapping operations in both production and job-shop environments.

Key Features

• 1/2-13 UNC right-hand thread form, class of fit 3B, thread limit H5
• Cobalt high-speed steel construction for improved heat and wear resistance
• TiN coating reduces friction and extends tool life in abrasive materials
• Plug chamfer with 4 to 4.5 chamfered threads for standard through-hole starts
• Thread forming (chipless) design produces stronger threads than cut tapping
• Compatible with alloy steel, carbon steel, stainless steel, aluminum, and die steel

Compatibility

Designed for through-hole thread forming in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces requiring a 1/2-13 UNC internal thread at class of fit 3B.

Installation Notes

Thread forming taps require a specific tap drill size for the material and class of fit — consult the OSG HY-PRO NRT series drill chart before selecting the pilot hole diameter. Because this is a forming tap, do not use drill sizes intended for cut taps, as the hole must be slightly larger to allow material displacement. Apply a high-quality forming tap lubricant or cutting fluid appropriate for the workpiece material before and during the tapping operation. Secure the workpiece and use a tapping chuck or controlled-feed CNC cycle to avoid tap breakage.