Wood Species Glossary: Hardness, Grain & Workability Reference

I ripped a chunk out of a red oak breadboard project because I grabbed the hardness number off one of those laminated wood-comparison charts you can buy at the woodworking show for about twelve bucks — the number on it was closer to white oak, and red oak fought me on every single pass with the spindle sander. That chart's job now is holding down a paint can in the garage. This page is the fix I built for myself: Janka hardness, grain, and workability notes for the species I actually reach for, pulled straight from the source instead of a poster that apparently rounds numbers to whatever looks tidy on a shelf.

I'm not a carpenter — I'm an IT project manager who built a deeply lopsided bookshelf during COVID and never really stopped. Half my garage is a shop now (my wife negotiated hard for the other half), and I've since built everything from cutting boards to a dining table she'll actually let guests sit at. I think of this table the same way I think of a good runbook at work: I don't want marketing copy or vibes, I want the number, where it came from, and whether the wood is going to burn my planer blade or glue up without a fight. Measure twice, check the source once — that's basically my whole system now.

Wood Species Comparison Table

The terms below trip people up more than the numbers do — I definitely mixed up open grain and closed grain out loud in front of a Rockler employee once, so here's the cheat sheet I wish someone had handed me that day.

Glossary of Technical Terms

Janka Hardness

The industry-standard measurement of how much a wood resists denting and wear — the force (in lbf) required to embed a .444 in (11.28 mm) diameter steel ball into the wood to half the ball's diameter (Wood Database). Higher number, harder wood, more resistance when you're planing or drilling it.

Open Grain

Wood with large longitudinal cells (vessels) that show up as visible pits or grooves on the surface — Oak and Ash are the classic examples. These are the boards that'll drink grain filler like it's on sale if you want a glass-smooth finish.

Closed Grain

Wood with pores too small to see with the naked eye, which is why Maple and Cherry come out of the finishing process looking smoother with a lot less effort on your part.

Workability

How easily a species cuts, shapes, and finishes with hand or machine tools without chipping, burning, or eating your blades. It's qualitative, not a number on a spec sheet — mostly it means "how much is this board going to make me regret my choices today."

Specific Gravity

The ratio of the wood's density to the density of water (Wood Database) — useful for estimating how heavy and how strong a piece is going to be before you haul it out to the truck.

Last verified: 2026-07-11

Sources

• The Wood Database: Black Walnut (Juglans nigra)
• The Wood Database: White Oak (Quercus alba)
• The Wood Database: Hard Maple (Acer saccharum)
• The Wood Database: Black Cherry (Prunus serotina)
• The Wood Database: Red Oak (Quercus rubra)
• The Wood Database: White Ash (Fraxinus americana)
• The Wood Database: Yellow Poplar (Liriodendron tulipifera)
• The Wood Database: Eastern White Pine (Pinus strobus)
• The Wood Database: Western Red Cedar (Thuja plicata)
• The Wood Database: Teak (Tectona grandis)
• The Wood Database: Janka Hardness (technical article)
• The Wood Database: Specific Gravity (technical article)