Seco 75056400 Lh Mwln Indexable Turning Toolholder

Product Description

The SECO 75056400 is a left-hand MWLN-style indexable turning toolholder designed for use on CNC lathes and manual turning centers. It accepts WN..33. series inserts secured by a combination clamp and pin holding method, providing rigid, repeatable insert location under interrupted cuts and continuous turning operations. The toolholder features a negative rake geometry with a -5.44 degree rake angle and a -6 degree lead angle, making it well suited for heavy material removal on a wide range of workpiece materials. The 0.625 inch by 0.625 inch square shank seats directly into standard tool blocks and turret stations.

This toolholder is intended for external turning applications in both production and job-shop environments. The Multiple Lock series design accommodates universal workpiece materials, covering ISO material groups H, K, M, N, P, and S, which span hardened materials, cast iron, stainless steel, nonferrous alloys, steel, and high-temperature alloys. Machinists and CNC operators working on medium-sized lathes will find the 4-inch overall length and 0.875-inch back-of-bar to cutting edge dimension compatible with common turret and tool-post configurations. Coolant-through capability is not included in this model.

Key Features

• Left-hand cutting direction for right-to-left turning passes
• Negative rake geometry (-5.44 degree rake angle) supports heavier depths of cut
• Clamp and pin insert retention for positive, repeatable insert seating
• Accepts WN..33. inserts with a 3/8-inch (0.3750 inch) inscribed circle
• Steel toolholder body for rigidity and durability in production turning
• Compatible with ISO material groups H, K, M, N, P, and S for universal turning use

Compatibility

Accepts WN..33. series indexable inserts with a compatible insert size code of WN33 and a 3/8-inch inscribed circle. Designed as an OEM-style MWLN left-hand turning toolholder for use in standard square-shank tool blocks and turret stations on CNC and manual lathes.

Installation Notes

Installation should be performed by a qualified machinist or CNC setup technician. Power down and lock out the machine spindle before seating or removing the toolholder from the turret or tool post. Ensure the shank bore or pocket is clean and free of chips before clamping. Follow the machine manufacturer's recommended clamping torque for toolholder retention hardware and verify insert seating before resuming cutting operations.