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Hardwood Lumber Grades and Size Rules: NHLA and European Standards

Reference hub · Last reviewed 20 October 2026

A grade tells a buyer how much clear wood a board yields. Size rules tell the buyer how big a board is and how it is counted. This page sets out the NHLA hardwood grades side by side, shows where the measurement and size rules fit, and links to the detail pages. The NHLA rulebook governs. The figures here are typical values from published summaries.

Grade	Face rule	Minimum board size	Clear face yield	Smallest clear cutting
FAS	Poorer face must meet FAS	6 in wide, 8 ft long	83 1/3% (10/12)	4 in x 5 ft or 3 in x 7 ft
F1F	Better face FAS, poorer face No.1 Common	6 in wide, 8 ft long (trade summaries, check)	Better face 83 1/3%	As FAS on the better face
Selects	Better face FAS, poorer face No.1 Common	4 in wide, 6 ft long	Better face 83 1/3%	As FAS on the better face
No.1 Common	Poorer face decides	3 in wide, 4 ft long	66 2/3% (8/12) to under 83 1/3%	4 in x 2 ft or 3 in x 3 ft
No.2A Common	Poorer face decides	3 in wide, 4 ft long	50% (6/12) to under 66 2/3%	3 in x 2 ft
No.2B Common	As 2A, cuttings need only be sound	3 in wide, 4 ft long	As 2A	As 2A

Species such as walnut have modified rules. Grades change with the edition of the rulebook. Name the rule and edition in every quote.

How the pages relate

• Measure first. NHLA measurement rules explain surface measure and board feet. The number of cuttings a grade allows comes from surface measure.
• Then grade. Selects and F1F shows the grades where only one face has to be clear.
• European sizes. EN 1313-2 covers the size deviations European buyers write into contracts.
• European names. EN 13556 explains the trade names and codes on European quotes.
• Flooring and parts. Flooring stock grades lists the NWFA and NOFMA names, and dimension stock specifications shows how to write a cut-size order.
• Proof. The graded-lot report and the other papers are in lumber papers and certificates.

Our guides on NHLA hardwood lumber grades, hardwood grading rules compared and European oak lumber grades cover the grades in more depth.

Send your lumber RFQ with the grade, the rule and the edition, and we pass it to up to 3 mills or yards that carry it.

Detail pages

• FAS Lumber: What the Firsts and Seconds Grade AllowsFAS lumber explained: 6 in by 8 ft minimum board, 83 1/3% clear face cuttings, cuttings allowed per board size, the extra cutting rule and species exceptions.
• NHLA Measurement Rules: Surface Measure, Board Feet and Tally RoundingHow the NHLA rules measure hardwood lumber: surface measure, board feet by thickness in quarters, width and length rounding, and what a tally must show.
• Selects and F1F Hardwood Lumber: When One Clear Face Is EnoughWhat NHLA Selects and FAS One Face (F1F) mean next to FAS and No.1 Common: board size, face rules, yield, species exceptions and which parts can use them.
• EN 1313-2: Permitted Deviations and Preferred Sizes for Hardwood Sawn TimberWhat EN 1313-2 controls for hardwood sawn timber: sizes, permitted deviations, reference moisture, how it differs from NHLA quarters, and how to write it into an EU RFQ.
• EN 13556 Timber Names: How to Read Trade Names and Codes on a European QuoteEN 13556 sets the trade names and four-letter codes European buyers use for timber. See how a code relates to the botanical name and what to write on an RFQ.
• Hardwood Flooring Stock Grades: NWFA and NOFMA Names, Lengths and the EN 14342 NoteUnfinished hardwood flooring grades under the NWFA/NOFMA standard: Clear, Select, No.1 and No.2 Common, board length minimums, moisture and how EN 14342 differs.
• Hardwood Dimension Stock: Cut Size Specs, Face Rules and Yield MathHow to write hardwood dimension stock specs: finished and rough size, face rules, solid or glued blanks, moisture, tally by piece and the yield behind the price.
• Lumber Thickness in Quarters and Surfacing Codes: Rough, S2S, S4S and Edge OptionsHardwood lumber thickness in quarters from 4/4 to 16/4, rough and S2S sizes in inches and mm, KD scant allowance and the codes S1S, S2S, S4S, SLR1E.

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