Butterfly key size chart
Starting dimensions for bowtie inlays from 1-1/2" to 8" long, in inches and millimetres. Use them as-is or as a jumping-off point in the generator.
| Length | End width | Waist | Metric (L × W × waist) |
|---|---|---|---|
| 1-1/2" | 5/8" | 1/4" | 38 × 16 × 6 mm |
| 2" | 13/16" | 5/16" | 51 × 21 × 8 mm |
| 2-1/2" | 1-1/16" | 7/16" | 64 × 27 × 11 mm |
| 3" | 1-1/4" | 1/2" | 76 × 32 × 13 mm |
| 3-1/2" | 1-1/2" | 5/8" | 89 × 38 × 16 mm |
| 4" | 1-11/16" | 11/16" | 102 × 43 × 17 mm |
| 5" | 2-1/8" | 7/8" | 127 × 54 × 22 mm |
| 6" | 2-1/2" | 1" | 152 × 64 × 25 mm |
| 8" | 3-3/8" | 1-3/8" | 203 × 86 × 35 mm |
Choosing a size
- Match the piece. A small box lid wants a 1-1/2" to 2" key. A thick live-edge slab can carry 4" to 8" keys.
- Span the crack. The ends need solid wood on both sides of the crack, so the key's length should be several times the crack's width plus room for the ends to bite.
- Mind the waist. A narrow waist looks crisp but is the weakest part of the key. Keep it at least as wide as your router can reach into, and remember the key's grain must run along its length.
- Several small keys along a long crack often look better than one big one.
Why the corners matter
If you rout the recess, its inside corners keep at least the bit's radius. A 1/4" bit leaves 1/8" radius corners. Either round the key's corners to match (the generator's Soft style), use a smaller bit, or square the recess with a chisel.