Osg 1400130600 Thread Forming Tap 5/16-18 Unc Cobalt

Product Description

The OSG 1400130600 is a thread forming tap designed for 5/16-18 UNC applications in blind holes. Part of the HY-PRO NRT series, this tap uses a modified bottoming chamfer with 2 to 2.5 chamfered threads, allowing it to thread close to the bottom of a blind hole. Manufactured from cobalt high-speed steel with a bright finish, it carries a thread limit of H4 and is designed for right-hand threading. Overall length is 2.719 inches, with a thread length of 0.665 inches and a tapping depth of 1.126 inches. Machinists and tool-and-die technicians install this tap in production and repair environments where chip-free thread forming is preferred over cutting taps.

This tap is suited for blind hole threading operations across a range of metals including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The cobalt construction gives it added heat and wear resistance compared to standard high-speed steel, making it a practical choice for tougher or abrasive materials. It is used in machining centers, drill presses, and tapping machines where consistent H4 thread tolerance is required in production runs or precision repair work.

Key Features

• Modified bottoming chamfer with 2 to 2.5 chamfered threads for threading close to blind hole bottoms
• Cobalt high-speed steel construction for improved heat and wear resistance
• Thread forming design produces no chips, reducing risk of chip packing in blind holes
• H4 thread limit for consistent tolerance control on 5/16-18 UNC threads
• Right-hand thread direction, bright finish, no coolant-through requirement
• Shank diameter of 0.318 inches with a square size of 0.238 inches for standard tap holders

Compatibility

Designed for blind hole thread forming in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N apply. Compatible with standard tap holders and tapping machines accepting a 0.318-inch shank diameter.

Installation Notes

Thread forming taps are installed by machinists and CNC operators. Ensure the workpiece is securely fixtured and the spindle is properly aligned before tapping. Use the appropriate cutting fluid or tapping compound recommended for the workpiece material to reduce friction during the forming process. Always confirm the pre-drilled hole diameter matches the recommended forming tap drill size for 5/16-18 UNC threads before starting the operation.