Osg 1400107701 Thread Forming Tap 5-40 Unc Cobalt

Product Description

The OSG 1400107701 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting chips. Sized for 5-40 UNC threading with a modified bottoming chamfer of 2 to 2.5 threads, it works in blind hole applications where chip evacuation is a concern. The tap is manufactured from cobalt high-speed steel and finished with a steam oxide coating to reduce friction and improve tool life. Overall length is 1.938 inches with a shank diameter of 0.141 inches. Machinists and tool-and-die technicians use this tap in production and repair operations requiring a Class 3B fit with an H3 thread limit.

This tap is suited for blind hole threading in a wide range of materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The modified bottoming chamfer allows the tap to reach close to the bottom of a blind hole, making it a practical choice for tight-tolerance fastener applications in precision machining, aerospace fixtures, and industrial component repair. Right-hand thread direction is standard. No coolant-through capability is present, so external cutting fluid application is recommended when tapping steel or stainless steel.

Key Features

• Thread forming design eliminates chips, reducing the risk of chip packing in blind holes
• Cobalt construction provides heat resistance for tapping hardened and stainless steel
• Steam oxide coating reduces friction and extends tool life in production use
• Modified bottoming chamfer (2 to 2.5P) allows threading close to the bottom of blind holes
• H3 thread limit and Class 3B fit for tight-tolerance threaded connections
• Right-hand thread direction, compatible with standard tapping equipment and tap handles

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. Intended for use with standard 5-40 UNC tapping operations requiring a Class 3B fit.

Installation Notes

Thread forming taps require more torque than cutting taps and must be used with appropriate tapping fluid or cutting oil, particularly in steel and stainless steel. Ensure the tap is properly aligned with the pre-drilled hole before starting to avoid tap breakage or cross-threading. Use a torque-limiting tap handle or CNC tapping cycle to prevent overload. Follow shop safety procedures and secure the workpiece before beginning any tapping operation.