Osg 1400137301 Thread Forming Tap 3/8-24 Unf Cobalt

Product Description

The OSG 1400137301 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal 3/8-24 UNF threads without cutting or generating chips. It features 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 and finished with a steam oxide coating, this tap is built to handle demanding tapping operations in a range of ferrous and non-ferrous materials. It is sized at 2.9380 inches overall length with a right-hand thread direction and an H4 thread limit, making it a precision fit for controlled-tolerance threading work.

This tap is suited for blind hole threading applications in production and maintenance machining environments. The modified bottoming chamfer makes it appropriate for jobs where full thread depth close to the hole bottom is required. It is compatible with CNC machining centers, drill presses, and manual tapping setups. Machinists and tool and die technicians working in job shops, production facilities, and maintenance operations will find it applicable across a wide range of workpiece materials including alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum.

Key Features

• Thread forming design eliminates chips, reducing the risk of chip packing in blind holes
• Modified bottoming chamfer with 2 to 2.5 chamfered threads for threading close to hole bottom
• Cobalt HSS construction provides improved heat and wear resistance over standard M2 HSS
• Steam oxide coating aids lubrication retention and reduces galling during tapping
• H4 thread limit for controlled-tolerance UNF thread production
• Right-hand thread direction, suitable for standard tapping heads and tap holders

Compatibility

Designed for blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N apply. Intended for 3/8-24 UNF internal thread forming applications.

Installation Notes

Thread forming taps require a properly sized form tap drill hole, which is larger than a standard cut tap drill — consult the appropriate form tap drill chart for 3/8-24 UNF before drilling. Use a cutting and tapping fluid rated for the workpiece material; steam oxide coating supports lubrication but does not eliminate the need for coolant or lubricant. Secure the workpiece and use a calibrated torque-limiting tap holder when possible to prevent tap breakage, particularly near the bottom of blind holes. This work is typically performed by machinists or maintenance technicians following shop safety procedures.