Technical Specification · Free Download
Hard Maple Acer saccharum
Comprehensive technical specification for North American Hard Maple in solid wood form, tailored for Canadian CNC routing, planing, and joinery operations. Includes standard Canadian stock sizes, machinability parameters, common defects, and storage guidelines.
Category
Solid Wood
Industry
Millwork
Standard
Canadian Sizing (NHLA)
Version
1.0
Material Overview & Common Uses
Hard Maple (Acer saccharum), also known as Sugar Maple or Rock Maple, is a dense, closed-grain hardwood native to eastern North America, with significant Canadian supply from Ontario, Quebec, and the Maritimes. It is prized for its high Janka hardness (1450 lbf), excellent wear resistance, and uniform light cream to reddish-brown heartwood. Common uses include: CNC-machined furniture components (table legs, chair frames), butcher blocks, cutting boards, flooring (gymnasium, bowling alley lanes), turned spindles, musical instruments (drum shells, guitar necks), and high-end cabinetry. In Canadian fabrication shops, it is a staple for custom millwork and architectural joinery due to its stability when properly kiln-dried.
Core Technical Properties & Sizing
| Property | Metric Value | Imperial Value |
|---|---|---|
| Density (at 12% MC) | 705 kg/m³ | 44 lb/ft³ |
| Janka Hardness | 6450 N | 1450 lbf |
| Modulus of Rupture | 109 MPa | 15,800 psi |
| Modulus of Elasticity | 12.6 GPa | 1,830,000 psi |
| Crushing Strength | 54 MPa | 7,830 psi |
| Shrinkage — Radial | 4.8% | — |
| Shrinkage — Tangential | 9.9% | — |
| Shrinkage — Volumetric | 14.7% | — |
| Moisture Content (kiln-dried interior) | 6–8% | — |
| Moisture Content (exterior protected) | 8–10% | — |
Standard Canadian Stock Sizes (S4S — Surfaced Four Sides)
| Dimension | Available Sizes | Tolerance |
|---|---|---|
| Thickness | 4/4 (1.00″), 5/4 (1.25″), 6/4 (1.50″), 8/4 (2.00″), 12/4 (3.00″) | ±0.005″ (S4S) |
| Width (random, FAS yields 6″+) | 3″, 4″, 5″, 6″, 8″, 10″, 12″ | ±0.010″ (S4S) |
| Lengths (1′ increments) | 4′–16′ (8′ and 10′ most common) | — |
| Rough Lumber (RGH) | +1/16″ thickness, +1/4″ width | — |
Grading (NHLA)
| Grade | Clear Face Yield | Minimum Clear Cutting Size |
|---|---|---|
| FAS (First and Second) | 83.3% | 6″ × 8′ |
| Select | — | — |
| #1 Common | — | — |
| #2 Common | — | — |
Machinability, Tooling & Feeds
| Parameter | Recommended Setting | Notes |
|---|---|---|
| Tooling Material | Carbide (C2/C3) or PCD | HSS not recommended extended use |
| Spindle Speed (1/2″ bits) | 12,000–18,000 RPM | Reduce for bits 1″+ |
| Spindle Speed (1″+ bits) | 8,000–12,000 RPM | — |
| Feed Rate — Roughing | 150–250 IPM | 0.050–0.100″ depth per pass |
| Feed Rate — Finishing | 100–150 IPM | 0.010–0.020″ depth per pass |
| Chip Load (2-flute) | 0.010–0.020″ per tooth | — |
| Chip Load (4-flute) | 0.005–0.010″ per tooth | — |
| Cutting Method | Climb (CNC), Conventional (roughing) | Climb for clean edges |
| Planing — Knife Marks | 12–20 KPI | Sharp knives; feed 15–25 FPM |
| Sanding Grit Progression | 80 → 180 → 220 | Avoid burnishing |
| Boring — Dowel Holes | 3,000–4,500 RPM | 0.005–0.010″ clearance per side |
| Boring — Pocket Holes | 2,000–3,000 RPM | 15° stepped bits |
| Gluing — Interior | Type I or II PVA (e.g., Titebond III) | Flat within 0.005″ over 12″ |
| Gluing — Exterior | Polyurethane or Epoxy | — |
| Finishing | Pre-stain conditioner recommended | Oil-based enhances grain |
Common Defects & Quality Control
| Defect | FAS Allowance | #1 Common Allowance | Rejection Criteria |
|---|---|---|---|
| Knots (sound tight) | Not permitted | Up to 1/2″ | Loose knots; >1″ in #1 Common |
| Mineral Streak | Not permitted | ≤1/4″ width over 50% of face | Exceeds width or coverage |
| Bark Pockets (open) | Not permitted | <1/8″ diameter (closed) | Open bark inclusions |
| Wane | 1/6 of face width on one edge | — | Exceeds allowance; both edges |
| Checks (surface) | Not permitted | ≤1/16″ wide × 6″ long | Through splits |
| Stain (blue stain / fungal) | Not permitted | ≤10% of face | Exceeds 10% coverage |
| Bow (over 8′) | ≤1/4″ | ≤1/2″ | Exceeds tolerance |
| Crook (over 8′) | ≤1/8″ | ≤1/4″ | Exceeds tolerance |
| Twist (over 8′) | ≤1/4″ | ≤3/8″ | Exceeds tolerance |
| Cup (over 4″ width) | ≤1/8″ | ≤3/16″ | Exceeds tolerance |
| Moisture Content | 6–8% (interior) | 6–8% (interior) | >10% or <5% (over-dried) |
| Machining Defects | None permitted | None permitted | Burn, tear-out, snipe >0.005″, chatter |
Storage, Handling & Racking Guidelines
- Environment: Store in a climate-controlled area at 35–45% RH and 18–22°C (65–72°F). Avoid direct sunlight and HVAC vents.
- Racking: Use heavy-duty cantilever or A-frame racks with 4″ minimum spacing between boards. Support every 24″; for 8/4 and thicker, support every 36″.
- Stickering: Use 3/4″ × 1″ kiln-dried stickers (same species or softwood) spaced 12–16″ apart, aligned vertically. Stickers must be dry (<8% MC) to avoid staining.
- Stacking: Stack boards with stickers aligned; maximum stack height 4′ for 4/4, 6′ for 8/4. Use a top layer of sacrificial plywood to distribute weight.
- Handling: Use a forklift with padded forks or a vacuum lifter for large sheets. For individual boards, carry on edge (never flat) to prevent breakage. Use gloves to avoid oil/sweat transfer.
- Inventory Rotation: First-in, first-out (FIFO) to prevent age-related defects. Mark each bundle with date received, grade, and moisture content.
- Waste Management: Separate offcuts by size (>24″ for small parts, <24″ for firewood or biomass). Recycle sawdust and chips for particleboard or animal bedding.
- Safety: Use dust collection with 1-micron filtration (OSHA PEL for wood dust is 5 mg/m³). Hard Maple dust is a known irritant; use N95 masks and eye protection.