S: Insert shape code (Square geometry with 4 effective cutting edges).
E: Clearance angle designation (Features a 20° high-positive clearance angle, which significantly reduces cutting forces and resists built-up edge).
K: Tolerance class (Specifies precision parameters for the height, thickness, and inscribed circle of the insert matrix).
T: Clamping/fixing type (Countersunk central fixing hole with single-sided chip-control grooves).
12: Insert size code (Standard Inscribed Circle (IC) diameter of 12.0 mm to 13.2 mm depending on the specific edge styling).
T3: Thickness designation (Standardized insert thickness measuring 3.97 mm / 0.156 inches).
M: Tolerance modifier or specific corner style variant.