Sumitomo 186PALW Grooving Insert GCMN4008MG AC425K Gnd Series

Product Description

The SUMITOMO 186PALW is a solid carbide grooving insert engineered for precision external and internal grooving operations on CNC turning centers and lathes. Built to GCMN4008MG geometry with an AC425K CVD coating, it delivers a 4 mm cutting width and a maximum depth of cut of 25.4 mm (1 inch). The double-ended design extends tool life and reduces cost per edge. A positive rake angle of 5 degrees and MG chip breaker geometry work together to control chip evacuation in demanding cuts. This insert is installed and changed by machinists and CNC operators in production and job-shop environments.

The 186PALW is suited for grooving and parting applications where cast iron and similar K-category workpiece materials are the primary target. Its GND series designation places it in a family optimized for stable, repeatable grooving on both light-duty finishing passes and moderate stock-removal operations. The neutral hand orientation allows it to seat in compatible left- or right-hand toolholders using a size 4008 insert seat. The MG chip breaker geometry helps manage chip formation across a range of feed rates common in ferrous grooving work.

Key Features

• CVD-coated AC425K carbide grade optimized for cast iron (K-category) workpiece materials
• 4 mm cutting width with a 0.80 mm corner radius for consistent groove profile
• Maximum depth of cut of 25.4 mm, covering a wide range of groove depths in a single insert
• Double-ended insert provides two usable cutting edges per insert
• Positive 5-degree rake angle and MG chip breaker for controlled chip flow
• Compliant with ANSI and ISO 13399 standards for tooling data interchange

Compatibility

Designed for use in GND series toolholders accepting a size 4008 insert seat with GCMN-style insert geometry. Confirm holder seat size and clamping system compatibility before installation.

Installation Notes

Insert changes should be performed with the machine in a full stop and all axes locked per shop lockout/tagout procedures. Use the appropriate torx or hex key specified by the toolholder manufacturer when seating the clamping screw — do not overtighten. Inspect the insert pocket and seating surface for chips or debris before loading a new edge. Verify runout and tool offset after each insert index before returning the machine to cycle.