Osg 1400104901 Thread Forming Tap 4-40 Unc Bottoming Cobalt

Product Description

The OSG 1400104901 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting or producing chips. Sized at 4-40 UNC with a bottoming chamfer of 1 to 1.5 threads, it is built from cobalt high-speed steel and finished with a steam oxide coating to reduce friction and improve lubricity during the forming process. The H3 thread limit and Class 3B fit make it well-suited for precision threading applications in blind holes where dimensional consistency is critical. Machinists and tool-and-die technicians install this tap in CNC machining centers, tapping heads, and manual drill presses across production and maintenance environments.

This tap is rated for blind hole threading in a broad range of materials including alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. The bottoming geometry allows threading close to the bottom of a blind hole, making it a practical choice where thread depth is constrained. Applications typically include precision components, fastener bosses, and threaded inserts in industrial and aerospace-adjacent manufacturing. Material application codes P and N confirm suitability across ferrous and non-ferrous workpieces.

Key Features

• Thread forming design eliminates chips, reducing clogging risk in blind holes
• Cobalt construction provides heat resistance and extended tool life in tough alloys
• Steam oxide coating lowers friction and aids lubrication retention during tapping
• Bottoming chamfer with 1 to 1.5 chamfered threads enables threading to near-bottom depth
• H3 thread limit and Class 3B fit ensure consistent, precise thread geometry
• Right-hand thread direction, compatible with standard tapping toolholders and tap wrenches

Compatibility

Designed for use in blind hole threading applications across alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum workpieces. Compatible with standard 4-40 UNC toolholding and tapping chuck systems.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which differs from standard cutting tap pilot holes — consult a forming tap drill chart before use. Apply tapping fluid or cutting oil rated for the workpiece material to reduce torque and extend tap life. Secure the workpiece fully before tapping and ensure the tap is started square to the hole. A machinist or skilled tooling technician should perform setup; verify machine spindle speed is appropriate for the material and tap diameter before running production cycles.