Osg 1400108305 Thread Forming Tap 5-40 Unc Plug Cobalt Tin

Product Description

The OSG 1400108305 is a thread forming tap designed for producing internal threads without cutting, using material displacement to create strong, chip-free threads. Built from cobalt high-speed steel with a titanium nitride (TiN) coating, this plug-chamfer tap is engineered for demanding threading applications in hard and abrasive materials. It carries a 5-40 UNC thread form, H3 thread limit, and a Class 3B fit, making it suitable for precision thread production in through-hole applications. With an overall length of 1.938 inches and a tapping depth of 0.626 inches, it fits standard toolholding setups used in machining and fabrication environments. Licensed machinists and toolroom professionals are the primary users of this tap.

This tap is rated for through-hole threading in a broad range of materials including alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. Its cobalt construction provides heat resistance during high-speed tapping operations, and the TiN coating extends tool life by reducing friction and adhesion. The HY-PRO NRT series designation indicates it is optimized for roll-form tapping where chip evacuation is not a concern and thread integrity is critical. It is well suited for production machining, maintenance and repair operations, and precision fabrication work requiring a tight Class 3B fit.

Key Features

• Thread forming design produces chip-free threads through material displacement, eliminating the risk of chip packing in blind or through holes
• Cobalt high-speed steel construction provides superior heat and wear resistance compared to standard HSS
• TiN coating reduces friction, extends tool life, and improves performance in stainless steel and hardened steel
• Plug chamfer with 4 to 4.5 chamfered threads allows easy thread starting in through-hole applications
• H3 thread limit and Class 3B fit ensure precise, consistent thread geometry for high-tolerance assemblies
• Right-hand thread direction, compatible with standard tapping heads and CNC toolholders

Compatibility

Designed for through-hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces requiring a 5-40 UNC, Class 3B internal thread. Compatible with material application codes P and N per OSG series classifications.

Installation Notes

Thread forming taps require proper alignment and appropriate tapping fluid or cutting oil for the workpiece material — dry tapping is not recommended. Power down and secure the workpiece before tap engagement. Use a torque-limiting tapping head or CNC rigid tapping cycle to prevent tap breakage, especially in harder materials. Inspect the tap for wear or chipping before each use, as a damaged tap can produce out-of-tolerance threads.