Hertel K007283AS Sti Tap M4 X 0.7 Metric Coarse Plug Hss

Product Description

The HERTEL K007283AS is a spiral point STI tap designed for cutting STI (Screw Thread Insert) metric coarse threads in through-hole applications. It is ground from high-speed steel with a bright, uncoated finish and features a plug chamfer for standard starting conditions. At 2-3/8 inches overall length with a 2-flute spiral point geometry, this tap pushes chips ahead of the cutting edge rather than packing them behind, making it well suited for production tapping in through-hole setups. It produces M4 x 0.7 metric coarse STI threads to accept helical coil inserts that restore or reinforce threaded holes in softer base materials.

This tap is used in machining, maintenance, and repair operations where a standard M4 x 0.7 thread needs to be converted to accept a helical insert, such as a Heli-Coil style repair. Typical applications include aerospace, automotive, and general metalworking shops performing thread repair or original equipment manufacturing where insert-threaded fastener joints are specified. It is installed by machinists and maintenance technicians working in both production and repair environments. The plug chamfer makes it appropriate for through-hole tapping where chip evacuation ahead of the tap is practical.

Key Features

• Spiral point geometry pushes chips forward for clean through-hole tapping
• Cuts M4 x 0.7 STI metric coarse threads sized for helical coil inserts
• High-speed steel construction provides good toughness across a range of workpiece materials
• Bright, uncoated finish allows visual wear inspection during service
• Plug chamfer for standard starting in through-hole applications
• D2 thread limit for consistent tap-to-insert fit tolerance

Compatibility

Designed for use in through-hole STI metric coarse tapping applications requiring M4 x 0.7 thread form sized to accept standard helical coil screw thread inserts.

Installation Notes

Installation is performed by machinists or maintenance technicians using a tap wrench, tapping head, or CNC spindle with appropriate feed and speed for the workpiece material. The correct STI tap drill size must be used prior to tapping to achieve the proper pre-tapped hole diameter for insert acceptance. Apply cutting fluid appropriate for the base material to extend tap life and improve thread quality. Always ensure the tap is properly aligned with the hole axis before engaging to avoid tap breakage or thread distortion.