Osg 1400102505 Thread Forming Tap 2-56 Unc Cobalt Tin

Product Description

The OSG 1400102505 is a thread forming tap designed for 2-56 UNC internal threading in blind holes. Unlike cutting taps, thread forming taps cold-form threads by displacing material rather than cutting chips, producing stronger threads with better surface finish. This tap is manufactured from cobalt high-speed steel for added heat and wear resistance, and carries a TiN (titanium nitride) coating to further extend tool life. The modified bottoming chamfer, with 2 to 2.5 chamfered threads, allows threading closer to the bottom of blind holes than a standard plug or taper chamfer. It is part of the OSG HY-PRO NRT series and targets precision threading work in machine shops and production environments.

This tap is suited for blind hole threading applications across a range of materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The cobalt construction and TiN coating make it particularly effective where heat generation and tool wear are concerns, such as threading stainless steel or hardened alloys. It is sized for 2-56 UNC thread forms and is appropriate for CNC machining centers, drill presses, and tapping machines where a Class 3B thread fit is required.

Key Features

• Thread forming (chipless) design produces stronger threads by cold-working material rather than cutting
• Cobalt high-speed steel construction provides increased heat and abrasion resistance over standard HSS
• TiN coating extends tool life and reduces friction during tapping
• Modified bottoming chamfer (2 to 2.5 threads) enables threading close to the bottom of blind holes
• Right-hand thread direction, Class 3B fit, Thread Limit H2
• No coolant-through design; suitable for external coolant or cutting fluid application

Compatibility

Designed for 2-56 UNC blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material Application Codes P and N apply.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which differs from standard cut tap drill sizing — consult an OSG or published forming tap drill chart for the correct hole diameter before use. Ensure the workpiece and machine spindle are properly aligned to avoid tap breakage at this small diameter. Apply appropriate tapping fluid or cutting oil for the workpiece material, particularly when working with stainless steel or hardened alloys. When removing the tap from a blind hole, reverse rotation carefully to avoid damaging the formed threads.