Osg 1400105005 Thread Forming Tap 4-40 Unc Bottoming Cobalt

Product Description

The OSG 1400105005 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming 4-40 UNC internal threads in blind holes without cutting or producing chips. Rather than removing material, this tap displaces metal to create a thread form, producing stronger threads with improved surface finish compared to cut taps. Built from cobalt high-speed steel and finished with a titanium nitride (TiN) coating, it handles demanding applications across a wide range of ferrous and non-ferrous materials. With a bottoming chamfer of 1 to 1.5 threads, it is suited for threading close to the bottom of a blind hole. This tap is installed by machinists and tool-and-die professionals in CNC machining centers and manual tapping operations.

The 1400105005 is intended for blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The right-hand, 4-40 UNC thread configuration makes it a standard choice for small fastener applications in precision manufacturing, electronics assemblies, instrument fabrication, and tooling fixtures. The bottoming chamfer design maximizes usable thread depth when working in shallow blind holes where full-chamfer taps cannot reach full thread engagement near the hole bottom.

Key Features

• Thread forming (chipless) design produces stronger threads and eliminates chip evacuation concerns in blind holes
• Cobalt construction provides heat and wear resistance beyond standard HSS taps
• TiN coating reduces friction and extends tool life across repeated tapping cycles
• Bottoming chamfer (1 to 1.5 threads) allows threading to near-bottom depth in blind holes
• H4 thread limit for controlled fit in standard 4-40 UNC applications
• Right-hand thread direction, compatible with standard tapping equipment and tap holders

Compatibility

Designed for blind hole thread forming in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces requiring 4-40 UNC internal threads. Material application codes P and N apply.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which is larger than a standard cut tap drill — consult the OSG or machinery handbook chart for the correct forming drill diameter for 4-40 UNC. Use a tapping fluid or cutting oil appropriate for the workpiece material, especially with stainless and alloy steels. Secure the tap in a rigid tap holder or floating tap head to prevent breakage on this small-diameter tool. On CNC equipment, verify spindle speed and feed rate are set for thread forming, not cutting.