Osg 1400138305 Thread Forming Tap 3/8-24 Unf Plug Cobalt Tin

Product Description

The OSG 1400138305 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting or producing chips. Operating on the 3/8-24 UNF thread standard with a plug chamfer, this tap displaces material rather than removing it, resulting in stronger thread forms with improved surface finish. Constructed from cobalt high-speed steel and finished with a titanium nitride (TiN) coating, it is built to handle demanding threading applications in a variety of ferrous and non-ferrous materials. It carries a Thread Limit of H5 and a Class of Fit of 3B, making it suitable for precision threading work in production and maintenance environments. Licensed machinists and tool-and-die technicians are the primary users.

This tap is rated for through-hole threading applications. It is suited for use in alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. The plug chamfer with 4 to 4.5 chamfered threads makes it appropriate for through-hole entry where the tap has adequate travel beyond the finished thread. It performs well in CNC machining centers, manual lathes, and drill press setups where controlled feed rates and adequate lubrication can be maintained.

Key Features

• Thread forming design displaces material rather than cutting, producing chip-free threads with higher strength
• Cobalt high-speed steel construction provides heat and wear resistance in tough materials including hardened steel and stainless steel
• TiN coating reduces friction and extends tool life in production threading cycles
• H5 thread limit and 3B class of fit ensure dimensional accuracy for precision assemblies
• Plug chamfer with 4 to 4.5 chamfered threads designed for through-hole applications
• Right-hand thread direction; no coolant-through feature required for typical application range

Compatibility

Designed for through-hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces requiring a 3/8-24 UNF internal thread form.

Installation Notes

This tap is installed by machinists using a tapping head, CNC rigid tapping cycle, or manual tap wrench with appropriate torque control. Because thread forming requires higher torque than cutting taps, use a lubricant or cutting fluid rated for the workpiece material before beginning. Verify spindle speed and feed rate match the tap manufacturer recommendations for the material being threaded. Never reverse the tap under power without confirming the machine setup supports it, and inspect the tap for wear or deformation before each production run.