Accupro 12865-01T 1/4-28 Unf Bottoming Thread Forming Tap Tin

Product Description

The ACCUPRO 12865-01T is a thread forming tap designed for cutting 1/4-28 UNF internal threads in blind hole applications. Unlike cutting taps, this forming tap displaces material rather than removing chips, producing stronger threads with a burnished finish. It is manufactured from powdered metal high-speed steel and coated with titanium nitride (TiN) for improved wear resistance and longer tool life. With a bottoming chamfer of 2.5 threads, it reaches close to the bottom of a blind hole, making it well suited for tight-tolerance work. Machinists and toolroom technicians use this tap in CNC machining centers, drill presses, and hand-tapping operations on ductile metals.

This tap is intended for blind hole threading in ductile materials such as aluminum, mild steel, and other formable metals where chip evacuation is a concern. The thread forming action eliminates chips entirely, reducing the risk of chip packing in deep blind holes. With an H5 thread limit and a Class of Fit rating of 2B and 3B, it produces threads suitable for standard and close-tolerance fastener assemblies. It is a practical choice for production environments and job shops requiring consistent thread quality in 1/4-28 UNF applications.

Key Features

• Thread forming design displaces material rather than cutting, eliminating chips in blind holes
• Bottoming chamfer (2.5P) allows threading close to the bottom of a blind hole
• Powdered metal high-speed steel construction for improved toughness and wear resistance
• Titanium nitride (TiN) coating extends tool life and reduces friction during forming
• H5 thread limit supports Class 2B and 3B fit tolerances
• Single oil groove aids lubrication during the forming process

Compatibility

Designed for use in blind hole threading operations requiring 1/4-28 UNF thread form. Compatible with standard tap holders and floating tap adapters sized for a 0.255-inch shank diameter. Suitable for use in CNC machining centers, drill presses, and tapping arms.

Installation Notes

Thread forming taps require a properly sized forming tap drill — consult a thread forming drill chart for the correct hole diameter specific to the workpiece material before use. Apply cutting or tapping fluid rated for thread forming operations; do not run dry. Secure the tap in a properly aligned holder to avoid cross-threading or tap breakage. Power down spindle and secure the workpiece before changing or inspecting the tap.