Osg 1400137505 Thread Forming Tap 3/8-24 Unf Cobalt Tin

Product Description

The OSG 1400137505 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting. It produces 3/8-24 UNF right-hand threads using a modified bottoming chamfer with 2 to 2.5 chamfered threads, making it well suited for blind hole applications where thread depth is critical. The tap is manufactured from cobalt high-speed steel and coated with titanium nitride (TiN) to extend tool life and reduce friction during forming. Overall length is 2.938 inches with a thread limit of H6. Licensed machinists and tool-and-die technicians are the primary users of this tap in production and maintenance machining environments.

This tap is intended 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 modified bottoming chamfer allows the tap to form threads close to the bottom of a blind hole, maximizing usable thread depth. It is appropriate for CNC tapping centers, drill presses, and manual tapping operations where consistent thread geometry and hole strength are required. The H6 thread limit ensures dimensional accuracy within standard UNF tolerance specifications.

Key Features

• 3/8-24 UNF thread size with right-hand thread direction
• Modified bottoming chamfer with 2 to 2.5 chamfered threads for close-to-bottom blind hole threading
• Cobalt HSS construction for strength and heat resistance in demanding materials
• TiN coating reduces friction and extends tool life in high-cycle applications
• H6 thread limit for controlled dimensional accuracy
• Thread forming design produces no chips, eliminating chip-clearing issues in blind holes

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 larger than that used for cut taps — consult the appropriate forming tap drill chart for 3/8-24 UNF before drilling the pilot hole. Use a tapping fluid or cutting oil rated for the workpiece material to reduce forming torque and extend tap life. Ensure the tap is properly aligned with the hole axis before applying torque; misalignment in blind holes can cause tap breakage. This tap does not require chip-clearing reversal cycles but the machine spindle must be capable of reversing for tap extraction.