Osg 1405000908 Thread Forming Tap 2-56 Unc Bottoming Hss

Product Description

The OSG 1405000908 is a thread forming tap in the EXOTAP VP-NRT series, designed for cold-forming internal threads without cutting or producing chips. It produces 2-56 UNC threads with a bottoming chamfer of 1 to 1.5 threads, making it well-suited for shallow blind holes where full thread depth close to the bottom is required. Constructed from powdered metal high-speed steel with a TiCN coating, it delivers improved wear resistance and surface hardness compared to conventional HSS taps. Licensed machinists, toolroom techs, and precision manufacturing shops are the primary users of this tap.

This tap is engineered for blind hole threading applications across a wide range of materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. Its cold-forming action work-hardens the thread flanks, resulting in stronger threads and no chip evacuation concerns in blind holes. The 2B class of fit and H3 thread limit make it appropriate for standard tolerance threaded assemblies in aerospace, automotive, and general precision manufacturing environments.

Key Features

• Bottoming chamfer (1 to 1.5 threads) allows thread forming close to the bottom of blind holes
• Powdered metal high-speed steel construction provides superior toughness and edge retention over standard HSS
• TiCN coating increases surface hardness and reduces friction for longer tool life
• Cold-forming design eliminates chips, reducing the risk of chip packing in blind holes
• H3 thread limit and 2B class of fit suit standard precision threaded assemblies
• Right-hand thread direction; compatible with standard tapping heads and CNC spindles

Compatibility

Designed for blind hole thread forming in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P, M, and N apply per ISO material classification.

Installation Notes

Thread forming taps require a specific tap drill size that produces the correct minor diameter for cold-forming rather than cutting; consult the OSG EXOTAP VP-NRT tap drill chart for the appropriate drill diameter for 2-56 UNC. Apply a suitable tapping fluid or cutting oil appropriate for the workpiece material before operation. Secure the workpiece firmly and ensure the tap is aligned perpendicular to the hole to prevent thread distortion or tap breakage. This tap is intended for use by qualified machinists and toolroom personnel with proper tapping equipment.