Osg 1400105200 Thread Forming Tap 4-40 Unc Cobalt

Product Description

The OSG 1400105200 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 threads with a modified bottoming chamfer of 2 to 2.5 threads, it is made from cobalt high-speed steel with a bright finish. The overall length is 1.875 inches and the tapping depth reaches 0.559 inches, making it well suited for blind hole threading in tight spaces. Machinists, tool-and-die makers, and CNC operators install this tap in production and repair applications where thread strength and finish quality are critical.

This tap is engineered for blind hole threading across a range of metals. Material applications include alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel, covering a broad cross-section of machining work in job shops, aerospace, automotive, and general manufacturing environments. The right-hand thread direction and H2 thread limit support standard tolerance requirements in precision assemblies. Its compact shank diameter of 0.141 inches suits small-bore work where clearance is limited.

Key Features

• Thread forming design eliminates chips, reducing risk of chip packing in blind holes
• Cobalt high-speed steel construction handles hardened and stainless steel applications
• Modified bottoming chamfer (2 to 2.5 threads) allows threading close to the bottom of a blind hole
• H2 thread limit for consistent, close-tolerance thread production
• Bright finish provides a smooth surface for monitoring tool wear
• Right-hand, 40 threads per inch, 4-40 UNC configuration for standard fastener compatibility

Compatibility

Designed for use in blind hole threading of alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces requiring 4-40 UNC internal threads.

Installation Notes

This tap is installed using a standard tap wrench, tapping head, or CNC tapping cycle with a rigid or floating holder sized for the 0.141-inch shank diameter. Secure the workpiece fully before tapping and ensure the pilot hole diameter is correct for thread forming in the target material. Thread forming taps require higher torque than cutting taps, so verify that the tapping equipment torque rating is adequate for the workpiece material. Coolant through is not supported on this tap; apply cutting fluid externally as appropriate for the material being tapped.