Tool-flo 554004LAC3A Threading Insert 4 Tpi Flo-lock

Product Description

The TOOL-FLO 554004LAC3A is a carbide threading insert designed for precision thread cutting in both internal and external applications. Built to the Acme thread standard at 4 threads per inch (TPI), this left-hand insert is finished with a Physical Vapor Deposition (PVD) coating process that improves surface hardness and wear resistance. The AC3A grade carbide substrate is suited for demanding threading operations where tool life and edge integrity are critical. Machinists and toolroom professionals install this insert into compatible Flo-Lock toolholders for consistent, repeatable thread form across production and repair work.

This insert is configured for left-hand Acme thread cutting and handles both internal and external thread profiles. It belongs to TOOL-FLO's Flo-Lock series, which is engineered for indexable threading applications. The FLA insert style designation indicates the specific geometry and seating configuration required. Typical applications include threading operations on lathes and CNC turning centers where Acme-profile threads are specified, such as lead screws, power screws, and actuator components.

Key Features

• Acme thread standard at 4 TPI for left-hand internal and external threading
• AC3A carbide grade with PVD coating for extended tool life
• FLA insert style geometry for use in Flo-Lock series toolholders
• Tip-to-top height of 0.2020 inches for precise profile positioning
• Cutting tip width of 0.0875 inches for accurate Acme thread form
• Insert thickness of 0.2550 inches for stable seating in the pocket

Compatibility

Designed for use with TOOL-FLO Flo-Lock series threading toolholders configured for the FLA insert style in size 4.

Installation Notes

This insert is installed by a machinist or toolroom technician into a compatible Flo-Lock indexable threading toolholder. Power down and lock out the machine before changing inserts. Use the correct torque wrench or insert-seating tool as specified by the toolholder manufacturer to avoid cracking the carbide. Inspect the pocket and clamping screw for wear or debris before seating the new insert.