Osg 1400125100 Thread Forming Tap 12-28 Unf Plug Cobalt H6

Product Description

The OSG 1400125100 is a thread forming tap designed for right-hand, through-hole threading in a wide range of metallic workpieces. Part of the HY-PRO NRT series, this plug-style tap is manufactured from cobalt with a bright finish and carries an H6 thread limit. It produces 12-28 UNF internal threads by displacing material rather than cutting chips, which results in stronger thread forms and eliminates the need for chip evacuation. The overall length is 2.375 inches, with a thread length of 0.496 inches and a tapping depth of 0.933 inches. The 0.22-inch shank diameter and 0.165-inch square size are suited for standard tap holders and machine chucks used in production and job-shop environments.

This tap is intended for through-hole threading applications in materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The plug chamfer, with 4 to 4.5 chamfered threads, allows the tap to start easily in a pre-drilled through-hole and is commonly used in CNC machining centers, drill presses, and manual tapping operations. It suits both production runs and maintenance or repair threading tasks where UNF thread geometry is specified.

Key Features

• Thread forming design displaces material to create stronger threads without cutting chips
• Cobalt construction provides heat and wear resistance in tough alloys and stainless steel
• H6 thread limit ensures consistent fit within standard UNF tolerance class
• Plug chamfer with 4 to 4.5 chamfered threads for reliable through-hole starting
• Right-hand thread direction compatible with standard tap holders and machine tooling
• No coolant-through requirement simplifies setup in general-purpose machines

Compatibility

Designed for through-hole threading of 12-28 UNF right-hand threads in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N apply.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which differs from standard cutting tap drill charts - consult UNF forming tap drill size references before drilling. Power down or lock out the machine before loading the tap into the holder. Use an appropriate tapping fluid or cutting oil suited to the workpiece material to reduce galling, particularly in stainless and alloy steels. Verify tap holder alignment before starting to avoid tap breakage or thread distortion.