Import BDNA-22593 Hand Sti Tap 5/16-24 Unf H2 Plug Chamfer

Product Description

The IMPORT BDNA-22593 is a hand STI tap designed for cutting Screw Thread Insert (STI) threads in preparation for installing helical thread inserts in worn, stripped, or damaged threaded holes. It is configured for 5/16-24 UNF threads with an H2 tolerance limit, which controls the size of the finished thread to ensure a proper fit with the mating insert. The plug chamfer provides a gradual lead-in, making it suitable for through-holes and most general-purpose tapping applications. With 4 flutes and a bright uncoated finish, this tap is used by machinists, HVAC technicians, plumbers, and other trade professionals performing thread repair in metal components.

This tap is applied wherever a 5/16-24 UNF STI thread needs to be cut prior to installing a helical coil insert, such as Helicoil-style inserts referenced under Helicoil reference number 5FPB. Typical use cases include restoring stripped threads in aluminum housings, cast iron components, and steel parts found in HVAC equipment, pumps, compressors, and general mechanical assemblies. It is intended for hand tapping operations and is not designed for power-driven machine tapping under load.

Key Features

• 5/16-24 UNF thread form with H2 tolerance limit for accurate STI thread sizing
• Plug chamfer for versatile use in through-holes and blind holes with adequate depth
• 4-flute design provides balanced cutting action in standard tapping conditions
• High-speed steel (HSS) construction offers good hardness and wear resistance for hand tapping in ferrous and non-ferrous metals
• Bright uncoated finish suitable for use with standard tapping fluids
• Helicoil reference number 5FPB for insert system compatibility identification

Compatibility

Designed for use with Helicoil-style STI thread insert systems, referenced as Helicoil reference number 5FPB. Suitable for hand tapping applications requiring a 5/16-24 UNF STI oversize thread in preparation for helical coil insert installation.

Installation Notes

This tap is intended for hand tapping only and should be used with a properly sized tap wrench. Apply an appropriate cutting fluid or tapping compound for the base material being threaded to extend tool life and improve thread quality. Ensure the workpiece is securely clamped before starting. Reverse the tap periodically during cutting to break chips and prevent binding, especially in deeper holes.