Osg 1400125601 Thread Forming Tap 1/4-20 Unc Bottoming Cobalt

Product Description

The OSG 1400125601 is a thread forming tap designed for cold-forming internal threads without cutting — displacing material rather than removing chips. Built from cobalt high-speed steel with a steam oxide finish, this bottoming-chamfer tap is suited for blind-hole threading operations where the formed thread must extend close to the bottom of the bore. The H5 thread limit provides a controlled fit tolerance for 1/4-20 UNC threads. With an overall length of 2.5 inches and a thread length of 0.594 inches, this tap fits standard tapping chucks and holders used in machine shop and field tapping setups. It is part of the HY-PRO NRT series from OSG.

This tap is designed for blind-hole threading applications across a broad range of materials including alloy steel, carbon steel, die steel, hardened steel, aluminum, and stainless steel — reflecting material application codes P and N. The bottoming chamfer of 1 to 1.5 threads makes it the right choice when thread runout must be minimized and full-depth engagement near the bottom of the hole is required. Typical users include machinists, tool and die makers, maintenance technicians, and production threading operations where chip-free forming is preferred over cutting taps.

Key Features

• Thread forming (chipless) design eliminates chip buildup in blind holes
• Cobalt high-speed steel construction provides heat and wear resistance in tough materials
• Steam oxide coating improves lubricity and reduces galling during tapping
• Bottoming chamfer (1 to 1.5 threads) maximizes usable thread depth in blind holes
• H5 thread limit for consistent fit tolerance on 1/4-20 UNC threads
• Right-hand thread direction; compatible with standard tapping attachments and CNC spindles

Compatibility

Designed for 1/4-20 UNC blind-hole threading in alloy steel, carbon steel, die steel, hardened steel, aluminum, and stainless steel. Part of the OSG HY-PRO NRT series, Series 14001. Shank diameter of 0.255 inches fits standard 1/4-inch tapping chucks and holders.

Installation Notes

Thread forming taps require proper lubrication and are typically run at lower spindle speeds than cutting taps — consult OSG published speed and feed data for the specific work material before use. Ensure the correct drill size for thread forming (larger than a cut-tap drill) is used to prepare the hole; using an undersized drill will overload the tap. Power down and lock out any machine before manually loading or unloading the tap from a holder. For hardened steel applications, verify the workpiece hardness is within the tap's rated material application range before proceeding.