Hertel K010306AS25 Thread Forming Tap 2-56 Unc Bottoming Hss

Product Description

The HERTEL K010306AS25 is a bottoming-chamfer thread forming tap designed for 2-56 UNC threading in blind hole applications. Made from high-speed steel (HSS) with a titanium nitride (TiN) coating, this tap displaces material to form threads without cutting chips, reducing the risk of chip buildup in blind holes. It carries a 2B class of fit and an H2 thread limit for consistent, accurate thread geometry. The overall length is 1.75 inches, with a thread length of 0.4375 inches and a shank diameter of 0.141 inches. It is suited for machinists and maintenance technicians working with small-diameter fastener threads in ferrous and non-ferrous materials.

This tap is intended for blind hole threading operations where chip evacuation is a concern and a full thread form close to the bottom of the hole is required. The bottoming chamfer (1-2 thread lead) allows threading closer to the bottom of a blind hole than plug or taper chamfer taps. Right-hand thread direction, 2-56 UNC thread standard, and standard square drive sizing make this tap compatible with conventional tap wrenches and CNC toolholders used in precision machining, assembly, and repair work.

Key Features

• Thread forming (chipless) design eliminates chip buildup in blind holes
• Bottoming chamfer with 1-2 thread lead for threading close to hole bottom
• High-speed steel construction for durability across ferrous and non-ferrous materials
• Titanium nitride coating extends tool life and reduces friction
• H2 thread limit ensures consistent 2B class of fit compliance
• Right-hand, 2-56 UNC thread standard for common small-fastener applications

Compatibility

Designed as an OEM-style replacement or direct-use thread forming tap for 2-56 UNC blind hole threading operations using standard tap wrenches or CNC toolholders with appropriate collet sizing for a 0.141-inch shank diameter.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which differs from a cutting tap drill size — consult a thread forming tap drill chart for the correct pre-drill diameter before use. Secure the workpiece and ensure the tap is aligned perpendicular to the hole to prevent tap breakage at this small diameter. Apply appropriate tapping fluid for the workpiece material to reduce friction and extend tool life. This tool is intended for use by qualified machinists or technicians familiar with small-diameter tapping procedures.