Regal Cutting Tools 007072AS Hand Sti Tap 3/8-16 Unc

Product Description

The REGAL CUTTING TOOLS 007072AS is a hand STI tap designed to cut 3/8-16 UNC threads in Screw Thread Insert (STI) applications. STI taps cut an oversized thread that accepts a helical wire insert, restoring or reinforcing threads in aluminum, cast iron, and other materials where standard threads would strip or fail. This tap features a plug chamfer for general-purpose through-hole and moderately deep blind-hole tapping. Built from high-speed steel with a bright uncoated finish, it carries an H3 thread limit and 4 flutes, making it a solid choice for hand tapping operations in maintenance, repair, and production environments. Licensed machinists and maintenance technicians are the primary users.

This tap is used wherever STI thread inserts are being installed to repair damaged threads or to add insert-reinforced threads in new work. Typical applications include aerospace component repair, automotive engine work, and industrial equipment maintenance where thread pullout strength must exceed what a standard tapped hole provides. The plug chamfer style suits most standard through-hole applications and moderately deep blind holes. It is sold individually and is intended for hand tapping use, not power-driven tapping equipment.

Key Features

• STI thread form cuts oversized 3/8-16 UNC thread to accept helical wire inserts
• H3 thread limit for consistent fit with Class 3B tolerance requirements
• Plug chamfer provides gradual thread lead-in, suited to through-holes and moderate blind holes
• 4-flute design for balanced cutting action during hand tapping
• High-speed steel construction handles a wide range of workpiece materials
• Bright uncoated finish - no coating buildup that could affect thread tolerance

Compatibility

Designed for use with standard 3/8-16 UNC STI helical wire thread insert systems. Verify insert supplier specifications to confirm tap size requirements before use.

Installation Notes

This tap is intended for hand tapping only; use a proper tap wrench and apply consistent axial pressure to avoid tap breakage. Secure the workpiece firmly before tapping, and use a cutting fluid appropriate for the workpiece material to extend tap life and improve thread finish. Back the tap off periodically to break chips, especially in blind holes. Follow shop safety practices and applicable standards when working with cutting tools and inserts.