🔩 Faceplate Screw Circle Reference Chart
A general reference for choosing a faceplate screw circle diameter relative to your blank size, to keep the mounting screws within the waste area (bottom) of the finished piece.
What the ranges are built around
The chart is not a formula, it is two clearances. A faceplate screw has to sit in wood that will be cut away or buried in the foot, and it has to stop short of the finished inside:
screw circle < diameter of the waste or foot area
screw depth < blank thickness - finished interior depthBecause a foot grows far more slowly than a bowl, the circle takes a shrinking share of the blank as blanks get bigger:
| Blank | Screw circle | Share of diameter |
|---|---|---|
| 6 in | 2-2.5 in | 33-42% |
| 10 in | 2.5-3 in | 25-30% |
| 14 in | 3-3.5 in | 21-25% |
| 18 in | 3.5-4 in | 19-22% |
Using it in the workshop
In practice the screw circle is fixed by the faceplate you own, so read the chart backwards: it tells you which faceplate suits the blank in front of you, and where a 15 in blank has outgrown a small one. Mark the circle on the blank before you drill and check it falls inside the base you have drawn, not across the wall line.
Frequently asked questions
What size screw circle for a 12 inch bowl blank?
The chart puts a 12 to 14 in blank at a 3 to 3.5 in circle, roughly a quarter of the diameter. Whether that works depends on the foot you have planned: the screws must all land inside it.
How deep should faceplate screws go into the blank?
Deep enough to hold in sound wood, and shallow enough that the tips never reach the depth you intend to hollow to. Work out the gap between blank thickness and finished interior depth first, then pick a screw length that fits inside it and matches what the faceplate maker specifies.
Can I use drywall screws in a faceplate?
Faceplate makers specify a screw type for their plates, and hardened construction screws are widely cautioned against because they are brittle in shear. Use what the maker calls for.