Osg 1400130700 Thread Forming Tap 5/16-18 Unc Cobalt

Product Description

The OSG 1400130700 is a thread forming tap designed for cold-forming internal threads without cutting or removing material. Part of the HY-PRO NRT series, this tap produces 5/16-18 UNC right-hand threads in blind hole applications. It is manufactured from cobalt high-speed steel with a bright finish and carries a H5 thread limit. The modified bottoming chamfer with 2 to 2.5 chamfered threads allows threading close to the bottom of a blind hole. Overall length is 2.719 inches with a tapping depth of 1.126 inches and a shank diameter of 0.318 inches. Machinists and tool-and-die technicians install this tap in production and maintenance environments where thread quality and hole integrity are critical.

This tap is suited for blind hole threading in a range of metallic workpiece materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The thread forming action — rather than cutting — displaces material to create stronger, work-hardened threads with no chips to evacuate, making it especially practical in deep blind holes where chip packing is a concern. It is commonly used on CNC machining centers, drill presses, and tapping machines in both job shop and production settings.

Key Features

• 5/16-18 UNC thread size, right-hand direction, H5 thread limit for close-tolerance fits
• Modified bottoming chamfer (2 to 2.5P) for threading near the base of blind holes
• Cobalt high-speed steel construction for improved heat and wear resistance
• Thread forming design produces chip-free, work-hardened threads
• Bright finish with no coolant-through requirement
• Square drive end: 0.238 inches square size, 0.375 inches square length for positive torque engagement

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.

Installation Notes

Thread forming taps require a specific tap drill size that differs from cutting taps — consult the OSG HY-PRO NRT series tap drill chart for the correct hole diameter before machining. Proper lubrication or tapping fluid is essential when forming threads in steel and stainless steel to prevent galling and tap breakage. Secure the workpiece and use a calibrated torque-controlled tapping attachment or CNC rigid tapping cycle to avoid overloading the tap. Inspect the tap for wear or deformation before each use, especially in hardened steel applications.