glossary
Rake Angle — Industry Glossary Entry
Definition of rake angle in industrial cutting: the angle of the front face of the cutting edge measured from vertical, and how positive vs negative rake.
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Rake Angle is the angle of the front face (the face that contacts the substrate first) of an industrial cutting edge, measured from a line perpendicular to the cut. A positive rake angles the face away from the cut, reducing the cutting force; a negative rake angles it into the cut, increasing the force but improving edge strength.
Rake angle, by substrate
- Paper and film: +5° to +15° (positive, to reduce cutting force and prevent drag)
- Plastic film: +10° to +20° (more positive for clean cut)
- Soft plastic, rubber: +15° to +25° (very positive, to slice rather than drag)
- Plate shearing: 0° to +3° (near-neutral, for edge strength on impact)
- Stainless plate: -3° to +3° (neutral, for wear balance)
- Hardened steel / AR plate: -5° to -10° (negative, for edge support)
Common mistakes
- Too much positive rake on a thin knife: the edge deflects, burr grows.
- Too much negative rake on a tough substrate: the cutting force is too high, the knife chatters, the substrate work-hardens.
- Asymmetric rake: the knife cuts in a curve instead of a straight line.
See also.
