Western hemlock is commonly sold and shipped together with amabilis fir under the commercial designation hem-fir (also often referred to as hem-bal). Hem-fir is primarily available as structural lumber for North America, Japan and other export markets.
In North America, structural grades are in accordance with the National Lumber Grades Authority (NLGA) rules for dimension lumber. Select Structural, #2 and better, and stud grades are the most common grades produced for North America, with squares being the most common Japanese product. Specialty in-house grades, lamstock and export grades such as E-120 for Japan are also marketed.
Appearance grades are produced according to NLGA rules. The most common are clears, shop lumber and moulding stock, although many potential appearance grades can be produced.
Stiffness / MOE (MPa) | Air dry | 12300 |
Strength / MOR (MPa) | Air dry | 81 |
Density (KG/M3) | Air dry | 429 |
Compression Parallel (Mpa) | Air dry | 46.7 |
Shear (Mpa) | Air dry | 6.48 |
Shrinkage (air dried-12%) | Tangential/radial ratio | 1.6 |
Title | Process | Performance | Comments |
---|---|---|---|
Machining | Planing | Good to average | A silky smooth finish is easy to achieve |
Shaping | Average | Easy, with good surface quality | |
Sanding | Good | Good sanding finish | |
Fastening | Screwing | Good | |
Nail retention | Good | ||
Gluing | Average | ||
Finishing | Staining | Good | The best finish is achieved with tight stain, or clear finish followed by nitrocellulose alkyd clear sealer and finish |
Painting | Good | ||
Drying | Ease of drying | Fair | Due to the high moisture content of this wood, longer kiln drying times are required |
Durablity | Natural decay resistance | Poor | Not appropriate for prolonged outdoor exposure |
Treatability | Good | Can be improved by incising |