Osg 1400127300 Thread Forming Tap 1/4-20 Unc Plug Cobalt

Product Description

The OSG 1400127300 is a thread forming tap designed for cold-forming internal threads without cutting or producing chips. Part of the HY-PRO NRT series, it produces a 1/4-20 UNC right-hand thread using a plug chamfer with 4 to 4.5 chamfered threads for smooth entry and progressive thread engagement. Built from cobalt high-speed steel with a bright finish, the tap delivers hardness and heat resistance suited for demanding tapping applications. Overall length is 2.5 inches with a thread length of 0.594 inches and a shank diameter of 0.255 inches. Licensed machinists, tool and die makers, and maintenance technicians install this tap in production and repair environments.

This tap is suited for through-hole threading operations in a wide range of metallic materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The thread forming method displaces material rather than cutting it, producing stronger threads with better surface finish in ductile materials. It is well-matched for CNC machining centers, drill presses, and tapping heads where consistent thread quality and tap longevity are priorities. The H6 thread limit designation ensures dimensional control within standard tolerance bands for 1/4-20 UNC threads.

Key Features

• Cobalt high-speed steel construction for increased heat and wear resistance in tough alloys
• Thread forming (chipless) design produces stronger threads and eliminates chip evacuation issues
• Plug chamfer with 4 to 4.5 chamfered threads for guided entry and gradual thread engagement
• H6 thread limit for controlled tolerance on 1/4-20 UNC right-hand threads
• Bright finish suitable for use with standard tapping fluids and cutting oils
• Through-hole threading application with a tapping depth of 0.933 inches

Compatibility

Designed for through-hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N confirm suitability across ferrous and non-ferrous ductile metals that accept cold-form tapping.

Installation Notes

Installation is performed by machinists and tool and die technicians using a tapping head, CNC machine, or hand tap wrench. Always apply an appropriate tapping fluid or cutting oil rated for the workpiece material before starting. Secure the workpiece fully before tapping and align the tap perpendicular to the hole to prevent tap breakage. Thread forming taps require a correctly sized forming tap drill hole diameter — consult the tap manufacturer drill chart for the proper forming drill size specific to 1/4-20 UNC before drilling.