Undercut

An undercut in machining and manufacturing is a feature or recess in a part that is inaccessible from above or below, often requiring special tooling or multi-axis machining to create. Undercuts can be intentional design features, such as grooves, slots, or recesses, or may occur unintentionally in complex geometries where certain areas are shielded by overhanging sections.

An undercut is a machining feature in which a recessed or hollowed area is created, typically beneath a surface or edge. Undercuts are commonly used to achieve specific design or functional purposes, such as interlocking parts or improving structural performance. However, these features often require specialised tooling and additional attention during maintenance to ensure the integrity of the design. Proper planning and tool selection are critical for creating precise undercuts while minimising equipment wear and tear.

Key Points about Undercuts

• Design
  Undercuts are often included in part designs for specific purposes, such as creating interlocking parts, grooves, or keyways, or for aesthetic reasons.

• Machining Requirements
  Since undercuts cannot be reached with standard cutting tools aligned with the primary machining axis, specialised tools, such as T-slot cutters, dovetail cutters, or multi-axis CNC machines, are required.

• Applications
  Undercuts are commonly used in mould making, casting, and parts that require snap-fit or interlocking features. They are also frequent in parts with complex geometries, such as housings and custom fasteners.

• Challenges
  Machining undercuts can increase production complexity, tool wear, and setup time. Proper planning and specialised tools are essential for achieving precise undercuts without damaging the workpiece.

An undercut is a recessed or shielded feature in a part that requires special tools or multi-axis machining to access and create, commonly found in parts with interlocking or complex geometries.