01. Spiral vs. Straight Bit Analysis
Spiral Bit
Features a twisted "spiral" flute similar to a drill bit. It is the core essential for professional woodworking.
Straight Bit
The classical form with vertical flutes. Ideal for rough work due to its affordability.
Technical Difference: Relief Angle
The biggest difference between standard metalworking endmills and SSOBOM Woodworking Spiral Bits is the Relief Angle. To achieve clean cuts in soft materials like wood, our bits are designed with a much larger relief angle to prevent burning and ensure chips don't stick to the tool.
Furthermore, 1-flute (Single) or 2-flute (Double) bits are primarily used in woodworking to provide ample space for sawdust evacuation. 3 to 4-flute bits often lead to clogging and increased friction, which frequently burns the material.
02. Upcut · Downcut · Compression
Upcut Bit
- Chips evacuated upward (Low load)
- Bottom surface is exceptionally clean
- May fray top surface; watch for material lifting
- Best for: Mortising, deep hole cutting
Downcut Bit
- Chips pushed downward (Holds material)
- Top surface is clean with no fraying
- Requires chip removal mid-process; frays bottom
- Best for: Dadoes, shallow grooves, surface work
Compression Bit
Up & Down Cut
"Clean finish on both Top and Bottom!"
A hybrid bit combining the advantages of both Upcut and Downcut. It pushes chips toward the center, ensuring no fraying on either the top or bottom edges of the material. It's the most advanced endmill that drastically reduces post-processing time.
03. Practical Guide & Pro Tips
Terminology & Tasks
Mortising
Creating vertical holes/slots to join wood. Upcut bits are best for chip evacuation.
Dadoes / Plunge
Wide and shallow grooves. Downcut bits ensure a clean top finish.
Selection Guide (T = Thickness)
- Below 10T: +-3~4mm Shank recommended
- Above 10T: +-5~6mm Shank recommended
- Cost-effective: Straight Bit
- Quality focused: Compression Bit