Teak (Tectona grandis)
Comprehensive technical specification for Teak solid wood, covering Canadian fabrication, machining parameters, standard stock sizing, common defects, and storage guidelines for industrial woodworking operations.
Material Overview & Common Uses
Teak (Tectona grandis) is a tropical hardwood renowned for its exceptional dimensional stability, natural oil content, and resistance to rot, decay, and moisture. It is one of the most durable woods in the world, with a Janka hardness rating of approximately 1,070 lbf (4,760 N). In Canadian fabrication and woodworking, teak is primarily used for high-end marine applications (decking, cabinetry, trim), outdoor furniture, architectural millwork, boat building, and custom joinery. Its natural oils make it challenging to glue and finish, requiring specialized preparation. Teak is typically sourced from plantations in Southeast Asia (Myanmar, Thailand, Indonesia) and is available in both plantation-grown and old-growth grades. Canadian shops often specify FAS (First and Select) or Select grade for appearance-critical work, with common thicknesses ranging from 4/4 to 8/4 (1 inch to 2 inches nominal).
Core Technical Properties & Sizing
| Property | Value / Specification |
|---|---|
| Density | 630 kg/m³ (39 lb/ft³) at 12% MC; plantation teak slightly lighter at ~550 kg/m³ |
| Janka Hardness | 1,070 lbf (4,760 N) |
| Modulus of Rupture (MOR) | 14,000 psi (96.5 MPa) |
| Modulus of Elasticity (MOE) | 1.6 million psi (11.0 GPa) |
| Crushing Strength | 7,500 psi (51.7 MPa) — parallel to grain |
| Shrinkage | Radial 2.5%, Tangential 5.0%, Volumetric 7.5% |
| Natural Oil Content | 5-10% by weight |
| Standard Thicknesses (Rough/S2S) | 4/4 (1.00"), 5/4 (1.25"), 6/4 (1.50"), 8/4 (2.00") |
| Standard Widths | Random 3" to 12" (FAS yield), up to 16" wide in 8/4 |
| Standard Lengths | Random 6' to 16', with 8-12' being most common |
| Moisture Content (Interior) | Kiln-dried to 6-8% MC |
| Moisture Content (Exterior/Marine) | 10-12% MC |
| Grain | Straight to slightly interlocked, coarse texture |
Machinability, Tooling & Feeds
Teak machines well but requires sharp, carbide-tipped tooling due to its silica content. Natural oils can cause gumming on blades and bits; use of a light mist of water or a non-stick coating (e.g., PTFE) on tooling helps reduce buildup. Pre-machining cleaning with a solvent (e.g., acetone) can remove surface oils for better glue adhesion.
| Operation | Tooling | Speed | Feed Rate | Notes |
|---|---|---|---|---|
| CNC Routing | 1/2" 2-flute carbide end mill | 12,000-18,000 RPM | 150-250 IPM | Chip load 0.008-0.012 in/tooth |
| Planing / Jointing | Carbide blades (12-15° hook, 20-25° clearance) | — | Light cuts (1/32" to 1/16") | Avoid tear-out on interlocked grain |
| Sawing (Crosscut) | Carbide-tipped blade | — | — | 40-60 teeth |
| Sawing (Rip) | Carbide-tipped blade | — | — | 24-30 teeth |
| Drilling | Brad-point or Forstner bit | 1,500-2,500 RPM | Pecking to clear chips | Use moderate speed |
| Sanding | Aluminum oxide / stearate paper | — | — | 80-220 grit; open-coat to prevent clogging |
Common Defects & Quality Control
| Defect | Description | QC Action / Mitigation |
|---|---|---|
| Silica Pockets | Hard, glass-like deposits that dull tooling | Inspect with strong light; avoid machining through |
| Gum Pockets | Resinous exudations that bleed through finishes | Pre-seal with shellac or a wash coat |
| Interlocked Grain | Causes tear-out during planing | Use low-angle cutterhead or climb cut on CNC |
| Checks & Splits | End checks and surface splits | Trim 1-2" from ends before use; reject if extensive |
| Wane | Bark edge on rough stock | Must be removed for FAS grade |
| Blue Stain | Fungal discoloration in plantation teak | Reduces appearance grade but not structural integrity |
| Knots | Small/tight or loose knots | Cut out or fill loose knots; reject if in critical area |
Acceptance Criteria: Measure MC with a pin-type meter at multiple points; reject stock with MC >12% for interior use. Check for twist, bow, and cup using a straightedge and feeler gauge — maximum allowable: 1/8" over 8' length for FAS. Visual inspection per NHLA grading rules.
Storage, Handling & Racking Guidelines
Store teak in a climate-controlled environment (40-60% RH, 15-25°C) to maintain target MC. Rack on a flat, level surface with stickers placed every 16-24" to allow air circulation. Use stickers of the same species or non-staining material (e.g., kiln-dried pine) to avoid discoloration.
- Do not store directly on concrete floors — use pallets or a vapor barrier.
- For long-term storage, cover with a breathable tarp to protect from dust and UV, but ensure airflow to prevent mold.
- Handle with clean gloves to avoid oil transfer from hands.
- For marine-grade teak, store in a dry area with low humidity to prevent surface checking.
- Rotate stock regularly (first-in, first-out) to minimize age-related defects.
- Separate by grade and thickness for easy retrieval. Avoid stacking heavy loads on top to prevent compression set.
- For CNC or machining cells, stage material in a conditioning room for 24-48 hours before processing to equalize MC.