Osg 1400126805 Thread Forming Tap 1/4-20 Unc Cobalt Tin

Product Description

The OSG 1400126805 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads in blind holes without cutting chips. Sized for 1/4-20 UNC threads, this tap is manufactured from cobalt high-speed steel and finished with a TiN (titanium nitride) coating to extend tool life in abrasive and hard materials. The modified bottoming chamfer, with 2 to 2.5 chamfered threads, allows threading close to the bottom of a blind hole. Overall length is 2.5 inches with a thread length of 0.594 inches and a tapping depth of 0.933 inches. Right-hand thread direction. Thread limit is H10. Installed by machinists, tool and die technicians, and maintenance trades.

This tap is suited for blind hole threading operations in alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. The cold-forming action displaces material rather than cutting it, producing stronger threads with a burnished surface finish. Typical applications include production tapping on CNC machining centers, manual drill press setups, and hand tapping in maintenance and repair environments where chip evacuation in blind holes is a concern.

Key Features

• Cold-forming design eliminates chips — ideal for blind hole applications
• Modified bottoming chamfer (2 to 2.5P) threads close to hole bottom
• Cobalt HSS construction for performance in hardened and stainless steels
• TiN coating improves wear resistance and reduces galling
• H10 thread limit for controlled fit in high-tolerance applications
• Right-hand thread direction, no coolant-through requirement

Compatibility

Designed for 1/4-20 UNC blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. Material application codes P and N. Part of the OSG HY-PRO NRT series (Series 14001).

Installation Notes

Thread forming taps require a specific forming tap drill size — do not use standard cut tap drill charts, as forming taps need a slightly larger hole to allow material displacement. Apply appropriate tapping fluid for the workpiece material before tapping; this is especially important with stainless and hardened steels. Secure the workpiece and ensure the tap is driven perpendicular to the hole axis to avoid thread distortion or tap breakage. Follow shop-specific speeds and feeds for the material being tapped.