Planer and jointer knives typically have a double bevel edge of 35° primary and 37° secondary for general woodworking. For hardwoods, a steeper bevel of 42° primary and 45° secondary is used to provide a stronger, more durable edge that resists chipping and lasts longer. This adjustment improves performance and tool life when cutting dense materials.
Planer and jointer knives typically feature a double bevel cutting edge. The standard configuration for most knives is:
- Primary bevel: 35°
- Secondary bevel: 37°
This design provides a sharp edge for general woodworking. For example, the Grizzly G6701 knife set uses this standard configuration.
Why Use a More Obtuse Angle for Hardwoods?
When working with hardwoods, the cutting edge experiences greater resistance. To handle this, the bevel angle is made more obtuse (steeper). This adjustment provides more steel behind the cutting edge, improving durability and reducing edge failure under heavy strain.
For hardwoods, a common configuration is:
- Primary bevel: 42°
- Secondary bevel: 45°
This design is used in premium blades such as the Japanese steel blade set T10152. Example:
Benefits of a Steeper Angle
- Stronger cutting edge: More steel supports the edge under pressure.
- Longer edge life: Holds sharpness longer when cutting dense materials.
- Reduced chipping: Better resistance to edge damage.
Summary
- Softwoods & general use: 35° / 37° bevel
- Hardwoods & heavy-duty use: 42° / 45° bevel
Choosing the right bevel angle ensures better performance and longer tool life.