Osg 1400126405 Thread Forming Tap 1/4-20 Unc Cobalt Tin H6

Product Description

The OSG 1400126405 is a thread forming tap designed for cold-forming internal threads without cutting, producing stronger threads by work-hardening the parent material. Built from cobalt high-speed steel with a titanium nitride (TiN) coating, it carries a 1/4-20 UNC thread form in a modified bottoming chamfer configuration with 2 to 2.5 chamfered threads. The H6 thread limit ensures consistent fit for standard tolerance applications. At 2.5 inches overall length with a 0.594-inch thread length and a 0.255-inch shank diameter, it is sized for use in hand-held tap handles or machine tapping setups. Licensed machinists and tooling technicians are the primary users of this tap.

This tap is intended for blind hole threading applications across a range of ferrous and non-ferrous workpiece materials. The modified bottoming chamfer allows the tap to reach closer to the bottom of a blind hole than a standard plug chamfer while still providing adequate lead-in for alignment. It is well suited for production or maintenance tapping in materials including alloy steel, carbon steel, stainless steel, aluminum, die steel, and hardened steel. The HY-PRO NRT series design supports both hand and machine tapping operations where thread forming rather than thread cutting is the preferred method.

Key Features

• Thread forming design cold-works the hole wall, producing stronger threads than cut tapping in ductile materials
• Cobalt high-speed steel construction provides elevated heat and wear resistance compared to standard M2 HSS
• TiN coating reduces friction and extends tool life in high-cycle or abrasive applications
• Modified bottoming chamfer with 2 to 2.5 chamfered threads allows tapping close to blind hole bottoms
• H6 thread limit suits standard tolerance fits for 1/4-20 UNC fastener applications
• Right-hand thread direction for use with standard tapping equipment

Compatibility

Rated for use in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N are assigned per the input data. Designed for blind hole threading operations in the OSG HY-PRO NRT series, product group 311.

Installation Notes

Thread forming taps require proper hole preparation with a tap drill sized specifically for forming, not cutting — consult an OSG HY-PRO NRT forming tap drill chart for the correct pilot hole diameter before use. Power down or disengage all rotating equipment before loading or changing taps. Use a cutting or tapping fluid compatible with the workpiece material to reduce heat buildup, especially in stainless steel or hardened steel applications. This tap does not produce chips, but the pilot hole must be clean and free of burrs before tapping to avoid galling or tap breakage.