Woodturning Blank Size Calculator
Bowl Blank
Calculate blank size needed for a turned bowl
Spindle Blank
Calculate blank size for spindle turning (pens, handles, legs)
Formula
Blank Diameter = Finished Diameter + Rounding Allowance; Blank Height = Finished Height + Bottom + Tenon
Frequently Asked Questions
How much bigger should a blank be than the finished piece?
For bowls, add 1" to diameter for rounding/truing and 0.75-1" to height for a tenon and waste. For spindles, add 0.5" to the cross section and 1" to length for mounting between centers.
What is a tenon in woodturning?
A tenon is a cylindrical projection turned on the base of a bowl blank that fits into a scroll chuck for mounting. It's typically 0.5-0.75" long and is removed or cleaned up in the finishing process.
Should I use green or dry wood?
Green (wet) wood is easier to turn and less dusty, but it will warp as it dries. Turn green blanks 10% oversized, then let them dry before final turning. Dry wood gives immediate final results.
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