Hertel K008307AS25 Spiral Point Tap 12-28 Unf Hss Tin

Product Description

The HERTEL K008307AS25 is a spiral point tap designed for cutting 12-28 UNF internal threads in through-hole applications. The spiral point geometry pushes chips forward ahead of the cutting zone, making it well suited for machine tapping in production environments where chip evacuation is a priority. Manufactured from high-speed steel with a titanium nitride (TiN) coating, this tap offers improved surface hardness and wear resistance compared to uncoated HSS. It carries an H3 thread limit and a 2B/3B class of fit, covering the most common tolerance requirements for general-purpose UNF threaded fastener applications.

This tap is used in metalworking and machining applications where a 12-28 UNF thread form is required. Plug chamfer geometry makes it appropriate for through-hole tapping in CNC machining centers, drill presses, and tapping machines. It is a standard choice for machinists, tool-and-die makers, and maintenance technicians working with fine-thread fastener assemblies in ferrous and non-ferrous materials. Coolant-through is not supported on this tap, so conventional flood coolant or cutting oil applied externally is the standard approach during use.

Key Features

• Spiral point geometry pushes chips forward, reducing clogging in through-hole tapping
• High-speed steel construction provides toughness across a range of workpiece materials
• TiN coating increases surface hardness and extends tool life versus uncoated HSS
• H3 thread limit with 2B/3B class of fit for standard general-purpose tolerance requirements
• Right-hand thread direction, plug chamfer for through-hole entry
• 15/16 inches thread length with 0.220 inch shank diameter

Compatibility

Designed for cutting 12-28 UNF internal threads in through-hole workpieces. Suitable for use in standard tapping chucks and holders accepting a 0.220 inch shank diameter.

Installation Notes

This tap is installed and operated by qualified machinists following standard tapping procedures. Secure the workpiece and ensure the tap is properly aligned before beginning the cut to avoid tap breakage. Apply appropriate cutting fluid or flood coolant externally throughout the tapping cycle. Use recommended tap drill sizing for the 12-28 UNF thread form to achieve proper thread engagement.