The WNMU series is a standardized designation for negative rake, square-shaped, indexable milling inserts. These inserts are a popular and cost-effective choice for robust face milling and shoulder milling operations on a wide range of materials.
Geometry: Square shape (90° corner angle) and a negative basic shape. This design provides exceptional strength and allows for four indexable cutting edges per insert, maximizing value.
Cutting Action: Designed for negative rake milling. This requires a holder with a built-in lead angle but offers superior edge strength, higher feed rates, and is ideal for roughing and heavy-duty material removal.
Applications: Primarily used in face mills, square shoulder mills, and high-feed mills for machining:
Carbon & Alloy Steel
Stainless Steel
Cast Iron
Other general-purpose materials
Nomenclature Breakdown:
W: Insert shape is typically a trigon (a modified triangle, often used interchangeably with square profiles in some general catalogs, but WNMU is universally a square).
N: Clearance angle is 0° (Negative rake insert).
M: Tolerances and design features.
U: Insert identification code (specific to the manufacturer's locking mechanism, hole type, and chipbreaker geometry).
Economical: Four cutting edges provide a low cost-per-edge.
Robust: The negative rake design and square shape can withstand high cutting forces and are resistant to chipping.
Versatile: A widely available standard insert type suitable for many roughing and semi-finishing applications.
High Feed Rates: Excellent for applications where high metal removal rates (MRR) are required.
