Hertel K010373AS25 Thread Forming Tap 1/4-28 Unf Plug Hss Tin

Product Description

The HERTEL K010373AS25 is a thread forming tap designed for right-hand, through-hole threading in a 1/4-28 UNF thread form. Unlike cutting taps, thread forming taps displace material rather than cut it, producing stronger threads with no chips. This tap is manufactured from high-speed steel and finished with a titanium nitride (TiN) coating that extends tool life by reducing friction and improving wear resistance. It carries a plug chamfer with 3 to 5 chamfered threads for easy starting in through-hole applications. The H4 thread limit and 2B class of fit make it suitable for standard inch-series fastener applications. Machinists and maintenance technicians use this tap in CNC machining centers, drill presses, and hand-tapping setups.

This tap is suited for through-hole threading operations in ductile materials such as aluminum, mild steel, and similar metals that respond well to the forming process. With a 1 inch thread length and 2.5 inches overall length, it fits standard tap holders and extension holders used in production and repair environments. The 0.2550 inch shank diameter and 0.1910 inch square size are compatible with common tap wrenches and machine holders in this size range. It is a single-piece, individual tap intended for job shop, production floor, or field maintenance use.

Key Features

• 1/4-28 UNF thread form with right-hand thread direction
• Plug chamfer with 3 to 5 chamfered threads for through-hole starting
• High-speed steel construction for durability in production environments
• Titanium nitride coating reduces friction and extends tool life
• H4 thread limit with 2B class of fit for standard inch-series thread tolerance
• No coolant-through design; suited for conventional tapping with applied cutting fluid

Compatibility

Designed as a direct-fit replacement for standard 1/4-28 UNF plug-style thread forming taps used in through-hole threading applications with compatible tap holders accepting a 0.2550 inch shank diameter.

Installation Notes

Thread forming taps should be installed by a qualified machinist familiar with form tapping procedures and appropriate tap holder torque settings for the work material. Always use a recommended tapping fluid or cutting oil suited to the workpiece material before beginning the tapping operation. Ensure the machine spindle or tap wrench is properly aligned to avoid tap breakage. Do not reverse the tap without confirming the holder and material type are appropriate for back-out forces.