Osg 1400105500 Thread Forming Tap 4-40 Unc Cobalt

Product Description

The OSG 1400105500 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting or producing chips. Sized for 4-40 UNC thread with a modified bottoming chamfer of 2 to 2.5 threads, it is built from cobalt high-speed steel with a bright finish. The tap carries a Class 2B fit and H5 thread limit, making it well suited for precision threading in production machining, toolroom work, and maintenance applications. Licensed machinists and tool-and-die technicians are the primary users of this tap.

This tap is intended for blind hole threading operations in a range of metallic workpiece materials. Its material application range covers alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The modified bottoming chamfer allows threading close to the bottom of a blind hole while still providing controlled thread engagement. It is a right-hand tap with a tapping depth of 0.559 inches, making it appropriate for shallow-to-moderate depth threading in small fastener applications across aerospace, automotive, and general machining environments.

Key Features

• Thread forming (chipless) design eliminates chip evacuation concerns in blind holes
• Cobalt high-speed steel construction for increased heat and wear resistance
• Modified bottoming chamfer (2 to 2.5P) for threading close to hole bottoms
• H5 thread limit and Class 2B fit for consistent, accurate thread geometry
• Compatible with alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel
• Right-hand thread direction with no coolant-through requirement

Compatibility

Designed for blind hole threading in 4-40 UNC applications across 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 are installed by machinists using a tap wrench, tapping head, or CNC tapping cycle with synchronized feed. Power down and secure the workpiece before beginning any tapping operation. Because this is a forming tap, proper lubrication and correct speed selection are critical to avoid tap breakage, especially in harder materials. Consult the machine tool manufacturer and the workpiece material specifications for recommended spindle speeds and cutting fluids before use.