Lumber Grade Guide

Understand hardwood (NHLA) and softwood grading systems and which grade to buy for your project.

Hardwood grades — NHLA

Hardwood lumber in North America is graded by the National Hardwood Lumber Association (NHLA). Grades are based on the percentage of a board that can yield clear, defect-free cuttings — not on the overall appearance of the board.

Grade	Min width	Min length	Clear face	Best for
FASFirsts & Seconds	6″+	8′+	83⅓%	Fine furniture, long clear runs, mouldings
FAS 1-FaceF1F / Selects	4″+	6′+	83⅓%	Cabinet face frames, mouldings, one clear face needed
SelectSel	4″+	6′+	83⅓%	Flooring, interior trim, cabinets
No. 1 Common#1C	3″+	4′+	66⅔%	Short furniture parts, flooring, raised panels
No. 2 Common#2C	3″+	4′+	50%	Rustic furniture, knotty panelling, shorts
No. 3A Common#3AC	3″+	4′+	33⅓%	Pallets, packaging, economy projects

Lumber is sold by the board foot. "Clear face" refers to the percentage of the board surface that must be free of defects. The back face may have more defects at the FAS and Select grades.

Softwood grades — dimensional lumber

Softwood dimensional lumber (2×4, 2×6, etc.) is graded primarily for structural strength under the Western Wood Products Association (WWPA) and Southern Pine Inspection Bureau (SPIB) systems.

Grade	Primary use	Notes
Select Structural	High-load structural framing	Strictest grain and defect limits
No. 1	General structural framing	Good strength, limited knots
No. 2	General framing, most common	Wider knots allowed; standard stud grade
No. 3	Light framing, blocking	More knots and defects; not for load-bearing without engineering
Stud	Wall studs only	Optimised for vertical loads; 8′ or 9′ lengths
Construction	Light framing	Similar to No. 2 for 2–4″ width lumber
Standard	Light framing, furring	Below Construction; economy grade
Utility	Blocking, crating, formwork	Lowest structural grade
C & Better Select	Appearance mouldings, trim	Virtually free of defects; highest appearance grade
D Select	Interior trim, panelling	Very few defects; one face may have minor blemishes

Tips for buying

For fine furniture: FAS or FAS 1-Face gives the longest, cleanest cuttings.
For cabinet parts & short components: No. 1 Common often gives the best value — most parts are under 24″ anyway.
For rustic or painted work: No. 2 Common or No. 3A can save significant money.
For structural framing: No. 2 is the workhorse grade used in most residential construction.

Always inspect boards at the lumber yard when possible. Two boards of the same grade can differ significantly in character — NHLA grade guarantees a minimum yield, not appearance.