Osg 1400105508 Thread Forming Tap 4-40 Unc Cobalt Ticn

Product Description

The OSG 1400105508 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting. Operating on a 4-40 UNC thread standard with a modified bottoming chamfer of 2 to 2.5 threads, it displaces material rather than removing chips, producing stronger threads with better surface finish. Built from cobalt high-speed steel with a TiCN coating, it handles the heat and wear demands of threading alloy steel, stainless steel, and hardened steel in production environments. Licensed machinists and precision machining professionals install this tap for blind hole applications where chip evacuation is a concern.

This tap is suited for blind hole threading in ferrous and non-ferrous metals including alloy steel, carbon steel, die steel, hardened steel, aluminum, and stainless steel. The H5 thread limit and Class 2B fit designation make it appropriate for standard commercial-tolerance fastener applications. Its compact 4-40 size targets small-diameter, fine-thread work common in instrument, aerospace, and electronic enclosure manufacturing.

Key Features

• Thread forming design eliminates chips, reducing tap breakage risk in blind holes
• Cobalt construction provides elevated heat resistance for harder work materials
• TiCN coating extends tool life and reduces friction in stainless and alloy steels
• Modified bottoming chamfer allows threading close to the bottom of blind holes
• H5 thread limit holds tight tolerance for Class 2B fit requirements
• Right-hand thread direction compatible with standard tapping equipment

Compatibility

Designed for blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces requiring 4-40 UNC internal threads to a Class 2B fit.

Installation Notes

Thread forming taps require higher torque than cutting taps and must be used with appropriate tapping fluid for the work material. Ensure the tap is properly aligned with the drilled hole before engagement to avoid cross-threading or breakage. Use a tapping stand, CNC machine, or drill press rather than hand-tapping freehand when possible. Always verify the correct form tap drill diameter for the material type, as it differs from standard drill charts used for cutting taps.