Osg 1400105301 Thread Forming Tap 4-40 Unc Cobalt

Product Description

The OSG 1400105301 is a thread forming tap designed for producing internal threads without cutting — displacing material rather than removing chips. Built from cobalt high-speed steel with a steam oxide coating, it is engineered for durability and reduced friction in demanding tapping applications. The 4-40 UNC configuration with a modified bottoming chamfer makes it well-suited for threading close to the bottom of blind holes, where 2 to 2.5 chamfered threads provide controlled thread lead-in. Machinists and tool-and-die professionals select this tap for applications where chip-free threading and clean thread form are priorities across a range of ferrous and non-ferrous materials.

This tap is suited for blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The modified bottoming chamfer allows threading to within a short distance of hole bottom, making it a practical choice for precision machined components in aerospace, automotive, and general manufacturing environments. It carries a Class 3B thread fit with an H3 thread limit, producing tight-tolerance threads appropriate for close-fit fastener assemblies. The right-hand thread direction is standard for conventional machine tapping setups.

Key Features

• Thread forming (chipless) design eliminates chip evacuation concerns in blind hole applications
• Cobalt HSS construction provides increased heat and wear resistance over standard M2 HSS
• Steam oxide coating reduces friction and improves lubrication retention during tapping
• Modified bottoming chamfer with 2 to 2.5 chamfered threads for threading near hole bottom
• H3 thread limit and Class 3B fit for tight-tolerance thread production
• Compatible with alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel

Compatibility

Designed for blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N indicate suitability for steel and non-ferrous material groups per standard machining classifications.

Installation Notes

Installation is performed by machinists using standard tapping heads, CNC machining centers, or manual tap handles rated for the torque requirements of the workpiece material. Power down or de-energize the machine and secure the workpiece before tool changes. Use appropriate tapping fluid or cutting oil for the specific workpiece material to extend tap life and improve thread quality. Follow shop-floor speeds and feeds for cobalt taps in the applicable material — do not exceed recommended RPM for the work material and tap diameter.