Pen blanks

Pen blanks - A quick guide to choosing the right blank size

It’s one of the most common questions in pen turning — and one of the easiest ways to avoid frustration before you even head to the lathe. Too short? You’ll come up shy at trimming. Too thin? You risk blowouts or exposed tubes. Too large? You’re just creating extra waste. Here’s a simple way to think about it: 

For most 7 mm / slimline-style kits: A 3/4" square by 5" blank is the standard go-to size. That gives you enough material for two barrels, a little trimming room, and comfortable turning. A 5/8" square blank can work, especially if you have some turning experience. But you’ll have less margin for error, especially if your drilling or alignment isn’t perfect.

• ♦ Beginners: 3/4" square is much more forgiving.

For larger single-barrel kits: Look at the tube length first. Add a little extra for trimming and squaring, and you’ll usually want a blank around 3/4" square by 5" or slightly longer.

For thicker or premium kits: Heavier hardware often looks better with more presence. That’s where 1" square blanks shine. They give you more design freedom and a more substantial finished pen.

Pro tip: always measure the tube before cutting your blank. Add 1/16"–1/8" extra length so you have clean material to square to. When in doubt, go slightly larger. Extra wood is easy to remove — missing wood isn’t.