Wood & Materials
Every board has a direction, a moisture content and a way of moving. The material you choose decides how a piece machines, how its joints hold, how it takes a finish and how it lasts.
Material Families
Solid wood keeps the structure of the tree. Manufactured boards rearrange it — to gain stability, width or economy, and to lose some of the character.
Specimen A · Solid wood
Specimens B–F · Manufactured boards
Thin veneers glued with the grain of each layer crossing the next.
Stable in width and length; edges show the plies.
Cases, cabinet backs, drawer bottoms, jigs
Wood fibres pressed with resin into a dense, uniform board.
No grain; very flat and paints well; edges and screws need care; swells if wet.
Painted panels, doors, templates
Wood particles and binder, finer at the faces, coarser in the core.
Economical and flat; weaker in screws and along edges than plywood.
Laminated cabinet boxes, shelving cores
A thin sheet of real wood, laid over a stable core.
Solid-wood appearance without solid-wood movement across a wide panel.
Figured panels, tabletops, doors
Strands, flakes or veneers bonded in designed layers — OSB, LVL and similar.
Engineered for strength or stability rather than appearance.
Structural and utility work, cores
Understanding Grain
Where a board came from in the log sets its figure and how it moves. Read the end grain before you choose a board for a part.
Plate G-1 · The faces of a board
Plate G-2 · Three ways through a log
Rings meet the face at a low angle
Rings near-perpendicular to the face (roughly 60–90°)
Rings at roughly 30–60° to the face
| Cut | Appearance | Movement |
|---|---|---|
| Flatsawn | Cathedral figure on the face; the most common and economical cut. | Moves most across its width and is more prone to cupping. |
| Quartersawn | Straight stripes; ray fleck in oak and sycamore. | Moves less in width and cups less; yields fewer boards per log. |
| Riftsawn | Straight grain on both face and edge — prized for legs. | Stable in width; the most wasteful cut to produce. |
Wood Movement
As the air grows more humid, wood takes on moisture and swells; as it dries, it shrinks. The change is not equal in every direction.
Moisture Content
Definition
MC % = (weight − oven-dry weight) ÷ oven-dry weight × 100
STAGE 1
Freshly sawn. Cell walls are saturated and the cells may still hold free water; moisture content can exceed 100% in some species.
STAGE 2
Free water is gone but cell walls are still saturated — commonly quoted around 25–30%. Shrinkage begins below this point.
STAGE 3
Stacked and stickered outdoors, lumber typically settles somewhere around 12–15%, depending on the climate.
STAGE 4
Furniture hardwood is commonly dried to about 6–8% so it starts close to indoor conditions.
STAGE 5
In use, wood settles to the humidity around it. In heated interiors that is often around 6–9%, varying by region and season.
Bring lumber into the shop and leave it stickered for days to weeks before final milling, so it can settle to your conditions.
Parts at different moisture contents move differently after assembly — a common cause of cracked panels and open joints.
Removing wood releases stress and exposes wetter core fibres. Rough-cut oversize, let it rest, then mill to final size.
Species Reference
Each species behaves in its own way at the saw, the plane and the finishing bench. None is better — each suits different work.
Juglans nigra
Janka1,010 lbf
Quercus alba
Janka1,360 lbf
Acer saccharum
Janka1,450 lbf
Prunus serotina
Janka950 lbf
Fraxinus americana
Janka1,320 lbf
Entandrophragma cylindricum
Janka1,410 lbf
Pinus strobus
Janka380 lbf
Reading the plates
Janka hardness is the force needed to press a 0.444″ steel ball halfway into the wood. Higher resists dents; it says nothing about strength or beauty.
Values are published averages. Individual boards vary with growth, density and moisture.
Browse all wood species| Species | Janka (lbf) | Radial % | Tangential % | T ÷ R |
|---|---|---|---|---|
| Black Walnut | 1,010 | 5.5 | 7.8 | 1.4 |
| White Oak | 1,360 | 5.6 | 10.5 | 1.9 |
| Hard Maple | 1,450 | 4.8 | 9.9 | 2.1 |
| Cherry | 950 | 3.7 | 7.1 | 1.9 |
| White Ash | 1,320 | 4.9 | 7.8 | 1.6 |
| Sapele | 1,410 | 4.6 | 7.4 | 1.6 |
| Eastern White Pine | 380 | 2.1 | 6.1 | 2.9 |
How Lumber Is Sold
Hardwood is usually sold rough or partly surfaced, by thickness in quarters of an inch and by the board foot. Know what the label means before you plan your parts.
Straight from the sawmill and kiln. Full nominal thickness, saw marks, often cupped.
Both faces planed; edges left rough for you to joint.
Faces planed and one edge straightened.
Faces and both edges finished — ready to cut to length.
End views. Brass lines mark planed surfaces; the dashed outline is the original rough size.
| Quarters | Rough thickness | Typical surfaced (S2S) |
|---|---|---|
| 4/4 | 1″ | 13/16″ |
| 5/4 | 1¼″ | 1 1/16″ |
| 6/4 | 1½″ | 1 5/16″ |
| 8/4 | 2″ | 1 3/4″ |
Surfaced thicknesses are common trade standards; individual suppliers vary.
| Nominal | Actual (dry, surfaced) |
|---|---|
| 1 × 6 | ¾ × 5½″ |
| 2 × 4 | 1½ × 3½″ |
| 2 × 6 | 1½ × 5½″ |
The board foot
One board foot is 144 cubic inches — 1″ × 12″ × 12″. Hardwood is usually priced by the board foot, measured at its rough thickness.
Work out board feetDefects & Board Selection
Sight down every board. Most faults cost yield rather than ruin a board — the question is how much of it you can use for your parts.
I-01
I-02
I-03
I-04
I-05
I-06
I-07
I-08
This is a practical checklist, not a formal lumber grade. Hardwood grading rules measure clear-cutting yield from a board and are published by grading associations.
Solid Wood & Plywood
Many good pieces use both: solid wood where it shows and is shaped, plywood where width and stability matter most.
| Aspect | Solid wood | Plywood |
|---|---|---|
| Movement | Moves across its width with humidity; must be allowed for | Very little movement in width or length |
| Stability | Can cup, bow or twist as it dries or is milled | Stays flat when stored and supported properly |
| Edges | Same wood all the way through; edges can be shaped | Plies show; usually edge-banded or hidden |
| Strength direction | Strong along the grain, weaker across it | Similar strength in both panel directions |
| Large panels | Glued up from several boards | Available in full sheets, commonly 4 × 8 ft |
| Joinery | Suits mortises, tenons, dovetails and shaped parts | Suits dadoes, rabbets, biscuits and screws; weak in end-grain-style joints |
| Finishing | Takes oils and stains through its depth; can be repaired by sanding | Thin face veneer — sand lightly and avoid cutting through |
| Typical use | Frames, legs, tabletops, exposed joinery | Cases, backs, drawer bottoms, shop fixtures |
Planning a sheet-goods project? Estimate the number of sheets
Material → Project
A starting point, not a rule. Budget, tools, appearance and where the piece will live all change the answer.
Plywood or a veneered engineered panel
Cross-laminated layers barely move in width, so the panel can be fixed rigidly.
Solid hardwood
Joints can be cut, shaped and shown; the wood looks the same through its thickness.
MDF or paint-grade plywood
Smooth, grainless faces take paint evenly; solid wood grain can telegraph through paint.
Species, finish and detailing together
Decay-resistant heartwood, a maintained finish and joints that shed water all matter — no single choice is enough.
Straight-grained solid wood suited to the method
Steam bending favours straight-grained species such as ash and white oak; bent laminations use thin strips.
From the Specimen Drawer
Choose the board for the part, let it settle before you mill it, and leave it room to move. The joinery and the finish will thank you.
