Jack Pine
Pinus banksiana · softwood · Northern North America · moderate movement
- Janka hardness 570 lbfred oak ≈ 1,290 lbf
- Density ≈ 30 lb/ft³specific gravity 0.43 at 12% MC
- Shrinkage — tangential 6.6%flatsawn width, green → ovendry
- Shrinkage — radial 3.7%quartersawn width
- T/R ratio 1.8 : 1higher = more cupping in flatsawn stock
Shop notes Scrappy northern SPF pine; knotty utility lumber that works fine when the design forgives knots.
Seasonal movement at a glance
Width change for jack pine across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:
| Board width | Flatsawn | Quartersawn |
|---|---|---|
| 6″ | 3/32″ (0.085″) | 1/16″ (0.048″) |
| 12″ | 5/32″ (0.170″) | 3/32″ (0.095″) |
| 24″ | 11/32″ (0.339″) | 3/16″ (0.190″) |
| 36″ | 1/2″ (0.509″) | 9/32″ (0.285″) |
Run your own numbers
Different width, different climate swing — the calculator below is preset to jack pine:
Typical swings:
Jack Pine questions
How much does jack pine move with the seasons?
A 12″-wide flatsawn jack pine board moves about 5/32″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 3/32″. Its tangential shrinkage is 6.6% and radial 3.7% (green to ovendry) — a moderate-movement wood.
How hard is jack pine?
Jack Pine rates about 570 lbf on the Janka scale — soft enough to dent in daily use (red oak is roughly 1,290 lbf). Density runs about 30 lb/ft³ at indoor moisture levels.
Is jack pine good for wide panels and tabletops?
Yes, with normal precautions: its 1.8:1 tangential-to-radial ratio is moderate. Still fasten solid tops so they can move across their width.
Similar species
Alaska Yellow-Cedar · Red Pine · Tamarack · Western Hemlock · Black Spruce · Baldcypress
Shrinkage, specific gravity, and hardness from the Wood Handbook, FPL-GTR-282 (2021 edition), USDA Forest Products Laboratory (public domain). Values are species averages — individual boards vary with growth conditions and how they were dried.