Osg 1405001108 Thread Forming Tap 2-56 Unc Modified Bottoming

Product Description

The OSG 1405001108 is a thread forming tap designed for cold-forming internal threads without cutting or producing chips. Manufactured from powdered metal high-speed steel (PM-HSS) and finished with a TiCN coating (trade name EXOTAP VP-NRT), this tap displaces material rather than removing it, producing stronger, work-hardened threads. It carries a 2-56 UNC thread specification with a modified bottoming chamfer of 2 to 2.5 threads, a class of fit of 3B, and a thread limit of H2. Overall length is 1.75 inches with a thread length of 0.437 inches and a shank diameter of 0.141 inches. It is installed by machinists and tooling technicians in precision manufacturing and fabrication environments.

This tap is suited for blind hole threading applications in a wide range of workpiece materials, including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The modified bottoming chamfer allows the tap to form threads close to the bottom of a blind hole, making it appropriate for tight-tolerance assemblies where thread depth is critical. It is used in production and repair settings where chip-free threading is required, such as aerospace, automotive, and precision instrumentation manufacturing.

Key Features

• Thread forming design eliminates chips for cleaner blind hole threading
• Powdered metal high-speed steel construction for improved wear resistance and toughness
• TiCN coating reduces friction and extends tool life across a broad range of materials
• Modified bottoming chamfer (2 to 2.5 threads) enables threading close to hole bottom
• Right-hand thread direction, class 3B fit, H2 thread limit for consistent tolerance control
• Compatible with alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel

Compatibility

Designed for blind hole thread forming in 2-56 UNC applications across alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P, M, and N apply.

Installation Notes

Thread forming taps require a properly sized forming hole — not a standard drill tap hole — so consult the appropriate forming hole chart for the workpiece material before use. Apply adequate tapping fluid or cutting oil compatible with the workpiece material to reduce heat buildup and extend tap life. Secure the workpiece and use a calibrated torque driver or tapping machine where possible to maintain consistent thread form and avoid tap breakage. Inspect the tap for wear regularly, as a worn forming tap can produce oversized threads or galling.