Osg 1400127305 Thread Forming Tap 1/4-20 Unc Plug Cobalt Tin

Product Description

The OSG 1400127305 is a thread forming tap designed for right-hand, through-hole threading in a 1/4-20 UNC configuration. Part of the HY-PRO NRT series, it is constructed from cobalt high-speed steel and finished with a titanium nitride (TiN) coating for extended tool life under demanding conditions. The plug chamfer style — with 4 to 4.5 chamfered threads — provides controlled thread engagement during the forming process. At 2.5 inches overall length with a 0.594-inch thread length and a shank diameter of 0.255 inches, this tap is sized for precision work in a standard machine tapping setup. It carries an H6 thread limit for close-tolerance applications. Machinists and tool and die professionals rely on this tap for consistent thread forming without chip generation.

This tap is suited for through-hole threading operations in a range of ferrous and non-ferrous workpiece materials including alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. It is appropriate for both CNC machining centers and manual tapping operations where a plug-style forming tap is required. The H6 thread limit makes it a strong choice for applications where dimensional accuracy and thread consistency are critical. No coolant-through capability is present, so external cutting fluid or tapping lubricant application is standard practice for this tool.

Key Features

• 1/4-20 UNC right-hand thread forming configuration for through-hole applications
• Cobalt construction provides hardness and heat resistance for difficult materials including hardened and stainless steel
• TiN coating reduces friction and extends tool life across high-volume tapping cycles
• Plug chamfer (4 to 4.5P) supports gradual thread engagement and smooth forming action
• H6 thread limit maintains tight tolerances for precision threaded connections
• Chipless forming action eliminates chip evacuation concerns in blind and through-hole applications

Compatibility

Designed for through-hole thread forming in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N confirm suitability across a broad range of metal types commonly encountered in machining and fabrication environments.

Installation Notes

Thread forming taps require adequate lubrication — apply an appropriate tapping fluid or cutting oil before and during use to reduce tool wear and improve thread quality. Ensure the tap is properly aligned with the drilled hole before engagement to prevent tap breakage, especially in harder materials. Secure the workpiece firmly and set spindle speed according to the workpiece material and tap manufacturer recommendations. Do not use this tap in blind holes unless tapping depth is confirmed to exceed the minimum required by the thread specification.