Osg 1400106000 Thread Forming Tap 4-40 Unc Plug Cobalt

Product Description

The OSG 1400106000 is a thread forming tap designed for creating internal threads without cutting, using cold-forming action to displace material rather than remove chips. Built from cobalt high-speed steel with a bright finish, this tap is part of the HY-PRO NRT series. It is configured for 4-40 UNC right-hand threads with a plug chamfer of 4 to 4.5 chamfered threads, making it suitable for through-hole threading operations. The H4 thread limit designation reflects the tolerance class for the produced thread. Overall length is 1.875 inches with a tapping depth of 0.559 inches. Machinists and toolroom professionals working in production and maintenance environments use this tap for precise, chipless thread forming.

This tap is suited for through-hole threading applications in a range of metallic workpiece materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. Its cobalt construction provides heat resistance and edge retention when tapping tougher alloys. The plug chamfer style requires a pre-drilled through-hole and is appropriate for production environments where consistent thread quality and tool longevity are priorities. It is sized for small-diameter work at the 4-40 UNC spec, common in instrument, electronics, and light mechanical assemblies.

Key Features

• Thread forming design produces chipless internal threads, reducing clogging risk in blind or through holes
• Cobalt high-speed steel construction provides heat and wear resistance in difficult-to-machine alloys
• Plug chamfer with 4 to 4.5 chamfered threads for standard through-hole entry and thread start
• H4 thread limit for controlled tolerance output on 4-40 UNC threads
• Right-hand thread direction compatible with standard tapping equipment and CNC machining centers
• No coolant-through design; suitable for use with surface-applied cutting fluids

Compatibility

Designed for through-hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces with material application codes P and N. Part of the OSG HY-PRO NRT series, Series 14001.

Installation Notes

This tap is installed by machinists using standard tapping chucks, CNC tapping attachments, or manual tap handles sized for the 0.141-inch shank diameter. Power down or disengage the machine spindle before securing or removing the tap. Apply appropriate tapping fluid or cutting oil to the workpiece before forming threads, as thread forming generates heat and pressure. Verify the pilot hole diameter matches the manufacturer recommendation for 4-40 UNC form tapping prior to use, as undersized or oversized holes will affect thread quality and tool life.