Dowel Joints: Strength & Design Showdown
My latest youtube video explores the strength of different dowel types and compares them to the Festool Domino for woodworking projects.
Dowel Strength by Diameter:
- Larger dowels are stronger (1/2" strongest, followed by 3/8" and 1/4"). Surprisingly, strength gain isn't proportional to diameter increase.
Dowel Strength by Length:
- Longer dowels provide significantly more strength (4" strongest, followed by 2" and 1"). Doubling the length nearly doubles the tensile strength.
Real-world Dowel Joint Tests:
Tests were conducted with glue and various dowel types under tensile and shear stress:
- Plain Dowel: Easy to find and customize, but requires prep work (cutting, chamfering). Strong (1645.9lbs tensile).
- Helical Dowel: Pre-cut, good for hidden joinery (1940.14lbs tensile).
- Fluted Dowel: Easy to insert, strong due to high glue surface area (1952.92lbs tensile). Consider this over Helical for easier use.
- Miller Dowel: Weakest (1574lbs tensile), awkward to use with specialty bit. Not recommended.
- Festool Domino (for reference): Very strong (2291lbs tensile), but not a fair comparison due to size and shape difference. Easier and faster to use.
Key Takeaways:
- While Festool Domino offers ease of use, dowels provide sufficient strength for most projects, especially with multiple supports.
- For hidden joinery, considerfluted dowels for their balance of strength and ease of use.
- Plain dowels are a versatile option for customizability, but require more prep work.