Hertel K007040AS Hand Sti Tap 10-32 Unf H3 Bottoming

Product Description

The HERTEL K007040AS is a hand STI tap designed for cutting Screw Thread Insert (STI) threads in tapped holes that will accept helical thread inserts. Sized at 10-32 UNF with an H3 thread limit, this tap produces the oversize thread profile required to accommodate coil-type thread inserts once installed. The bottoming chamfer style allows threading to the bottom of blind holes, making it the correct choice when full thread depth is required close to the hole floor. At 2.5 inches overall length and ground from high speed steel with a bright finish, this tap is built for hand tapping operations where dimensional control and edge retention matter.

This tap is used in repair and fabrication applications where a damaged or stripped threaded hole needs to be restored using a thread insert. Common installation scenarios include aerospace, automotive, machinery repair, and general metalworking where reclaiming stripped 10-32 UNF threads is required. The STI thread profile is specific to thread insert systems and is not interchangeable with standard 10-32 taps. A licensed machinist or experienced maintenance tech typically performs this work using a tap wrench with controlled torque to avoid tap breakage.

Key Features

• 10-32 UNF thread size for STI thread insert applications
• H3 thread limit for controlled oversize fit required by helical insert systems
• Bottoming chamfer for full-depth threading in blind holes
• 3-flute geometry provides chip clearance in hand tapping operations
• High speed steel construction for edge retention across ferrous and non-ferrous materials
• Bright finish — no coating — for straightforward regrinding when needed

Compatibility

Designed for use in STI thread insert tapping operations requiring a 10-32 UNF oversize thread profile with an H3 thread limit. Compatible with standard helical coil thread insert systems that specify a 10-32 STI tap. Verify insert manufacturer specifications before use to confirm the correct thread limit and tap geometry for your specific insert brand.

Installation Notes

This tap is intended for hand tapping and should be used with a proper tap wrench — never a power driver without torque control, as small-diameter high speed steel taps are susceptible to breakage under uncontrolled torque. Secure the workpiece before tapping and apply a suitable cutting fluid for the base material to extend tool life and improve thread finish. Back the tap out periodically to clear chips, especially in blind holes. Follow the thread insert manufacturer instructions for STI hole preparation, including correct drill size prior to tapping.