Osg 1400128005 Thread Forming Tap 1/4-28 Unf Bottoming Tin

Product Description

The OSG 1400128005 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting or producing chips. The tap is sized for 1/4-28 UNF threads with a bottoming chamfer of 1 to 1.5 threads, making it well suited for threading close to the bottom of blind holes. Manufactured from cobalt high-speed steel and finished with a titanium nitride (TiN) coating, it delivers elevated wear resistance and extended tool life in demanding production environments. This tap is installed by machinists, tool and die makers, and maintenance technicians working with CNC machining centers, drill presses, or manual tapping equipment.

The 1400128005 is intended for blind hole threading applications across a broad range of metallic workpiece materials. Its material application range includes alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel, covering both ferrous and non-ferrous work. The bottoming chamfer allows threads to be formed within a minimal distance from the hole bottom, which is critical in close-tolerance blind hole work. Right-hand thread direction is standard. This tap fits common machining and maintenance workflows in job shops, production facilities, and industrial maintenance operations.

Key Features

• Thread forming (chipless) design eliminates chip evacuation concerns in blind holes
• Cobalt high-speed steel construction for increased heat and wear resistance
• TiN coating extends tool life and reduces friction during forming
• Bottoming chamfer (1 to 1.5 threads) enables threading close to blind hole bottoms
• H6 thread limit for close-tolerance thread fits
• Compatible with alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel

Compatibility

Designed for blind hole thread forming in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Suitable for use with standard 1/4-28 UNF tapping fixtures, tap holders, and CNC rigid tapping attachments that accept the 0.2550-inch shank diameter of this tap.

Installation Notes

Thread forming taps require a specific forming tap drill size rather than a standard tap drill — consult the appropriate forming tap drill chart for 1/4-28 UNF before drilling the pilot hole. Ensure the tapping machine or spindle is set to right-hand rotation before use. Apply a suitable cutting or tapping fluid for the workpiece material to reduce friction and heat buildup during the forming operation. Inspect the tap for wear or deformation before each use; a damaged tap can strip threads or seize in the workpiece.