22: Represents the size of the insert, which features a 22 mm (0.500 inch) inscribed circle (IC).
I: Identifies it as an Internal threading tool.
R: Specifies that it is a Right-hand cutting insert.
N55: Indicates a 55° Partial Profile (non-cresting) V-thread form. It can cut a broad range of thread pitches sharing a 55-degree flank angle, such as Whitworth, BSPF, or BPT threads.
TC: Signifies a specialized chipbreaker geometry engineered for lower cutting forces and superior chip evacuation.
GM3225: The specific manufacturer material grade, consisting of a PVD multi-material TiAlN nano-structure coating. It provides exceptional wear resistance across P (Steel), M (Stainless Steel), K (Cast Iron), and S (Superalloys) material groups.