NORTH IOWALUMBER
Sizing Guide

Hardwood Grading Guide

A complete reference to NHLA hardwood grading rules — from premium FAS through No.3 Common — plus how reclaimed hardwood grading works differently.

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NHLA Grading Standards

The National Hardwood Lumber Association (NHLA) establishes the grading rules used throughout North America for hardwood lumber. These rules are based on the percentage of a board that can be cut into clear (defect-free) pieces of specified minimum sizes. Understanding these grades helps you select the right lumber for your project — and avoid paying for quality you do not need.

How Grading Works

Each board is evaluated by imagining it divided into a grid. The grader determines how many clear "cuttings" of specific minimum sizes can be obtained from the board. The percentage of clear face area determines the grade.

Clear Face vs. Defects

"Clear" means free of knots, splits, wane, decay, and other defects. Mineral streaks, slight color variation, and sound sapwood are generally not considered defects in most NHLA grades but may affect specific appearance requirements.

Pricing Impact

Higher grades command premium prices because they yield more usable clear material per board foot purchased. However, lower grades are often the smarter buy if your project involves shorter components, paint-grade work, or a rustic aesthetic.

Grade Summary at a Glance

GradeMin Board SizeMin Clear FaceTypical YieldCommon Name
FAS6" x 8'83-1/3%83 - 100%First and Seconds
F1F6" x 8'83-1/3% / 66-2/3%83 - 100%FAS One Face
Select4" x 6'83-1/3%83 - 100%Select
No. 1 Com3" x 4'66-2/3%67 - 83%Cabinet Grade
No. 2A Com3" x 4'50%50 - 67%Economy
No. 2B Com3" x 4'50%50 - 67%Economy (small cuts)
No. 3A Com3" x 4'33-1/3%33 - 50%Utility

Detailed Grade Specifications

Each NHLA grade has specific requirements for minimum board size, clear face percentage, cutting sizes, and yield. Here is a detailed breakdown of every standard grade.

FAS (First and Seconds)

The highest standard grade. Graded from the poorer face. Each board must yield large, clear cuttings. FAS boards are typically the widest and longest available.

Best Uses

Premium furniture, high-end cabinetry, architectural millwork, wide clear panels, visible faces where appearance is critical.

Minimum Board Size

6" wide x 8' long

Minimum Clear Face

83-1/3% (10/12ths)

Cutting Requirements

83-1/3% clear cuttings from the better face

Typical Yield

83.3% - 100%

FAS One Face (F1F)

Graded FAS on the better face and No. 1 Common on the reverse. An economical alternative to FAS when only one good face is needed. Pricing is typically 10-15% below FAS.

Best Uses

Furniture with one visible side, cabinet doors, table tops, wall paneling — any application where only one face is seen.

Minimum Board Size

6" wide x 8' long

Minimum Clear Face

83-1/3% one face / 66-2/3% reverse

Cutting Requirements

FAS quality on the better face, No. 1 Common on the reverse

Typical Yield

83.3% - 100% (good face)

Select

Essentially the same quality as F1F but with smaller minimum board dimensions. Allows 4" wide and 6' long minimums. This grade is especially useful for narrower furniture components and trim work.

Best Uses

Same applications as F1F. The smaller minimum board size makes this grade more economical for projects needing narrower or shorter pieces.

Minimum Board Size

4" wide x 6' long

Minimum Clear Face

83-1/3% one face

Cutting Requirements

FAS quality on the better face, No. 1 Common on the reverse

Typical Yield

83.3% - 100% (good face)

No. 1 Common

Often called "Cabinet Grade" — the workhorse of the hardwood industry. Most furniture and cabinet shops primarily use No. 1 Common because it offers an excellent balance of quality and value. The smaller clear areas yield pieces suitable for most components.

Best Uses

Kitchen cabinets, standard furniture, interior trim, shorter furniture components, cutting boards, small accent pieces.

Minimum Board Size

3" wide x 4' long

Minimum Clear Face

66-2/3% (8/12ths)

Cutting Requirements

66-2/3% clear cuttings from the better face

Typical Yield

66.7% - 83.3%

No. 2A Common

Also called "Economy Grade." Contains more knots, mineral streaks, and character marks. Significantly less expensive than higher grades. Ideal for rustic and farmhouse-style projects where character is valued.

Best Uses

Economy furniture, rustic projects, paint-grade millwork, flooring, smaller craft items, and any project where character marks are acceptable or desired.

Minimum Board Size

3" wide x 4' long

Minimum Clear Face

50% (6/12ths)

Cutting Requirements

50% clear cuttings from the better face

Typical Yield

50% - 66.7%

No. 2B Common

Similar yield to 2A Common but allows smaller cutting sizes. Typically the lowest grade sold at retail. Often mixed with 2A and sold as "No. 2 Common."

Best Uses

Paint-grade trim, concealed structural components, shop fixtures, jigs and templates, pallet wood, packaging.

Minimum Board Size

3" wide x 4' long

Minimum Clear Face

50% (6/12ths)

Cutting Requirements

50% clear cuttings, smaller minimums

Typical Yield

50% - 66.7%

No. 3A Common

The lowest standard NHLA grade. High percentage of defects, knots, and character marks. Very economical — often 40-60% cheaper than No. 1 Common. Can yield beautiful results in applications where character is the goal.

Best Uses

Flooring, pallet stock, crating, blocking, packaging. Also used creatively for rustic wall cladding, barn-door panels, and mixed-character art projects.

Minimum Board Size

3" wide x 4' long

Minimum Clear Face

33-1/3% (4/12ths)

Cutting Requirements

33-1/3% clear cuttings from the better face

Typical Yield

33.3% - 50%

Minimum Cutting Sizes by Grade

Each grade specifies not just the percentage of clear material, but the minimum size of individual clear cuttings that can be obtained. Higher grades require larger cuttings — which means longer, wider clear pieces for your project.

GradeMax Cuttings AllowedMin Cutting SizeSurface Measure Min
FASSM/4 (rounded down)4" x 5' or 3" x 7'6 SM
F1FSM/4 (better face)4" x 5' or 3" x 7'6 SM
SelectSM/4 (better face)4" x 5' or 3" x 7'4 SM
No. 1 CommonSM/3 (rounded down)4" x 2' or 3" x 3'3 SM
No. 2A CommonSM/2 (rounded down)3" x 2'3 SM
No. 2B CommonSM/2 (rounded down)3" x 2' (smaller allowed)3 SM
No. 3A CommonUnlimited3" x 2'3 SM

SM = Surface Measure, the board's area in square feet rounded to the nearest whole number. The maximum number of cuttings allowed scales with board size.

Yield vs. Cost: Choosing the Right Grade

A higher grade does not always mean a better value. The right grade depends on your component sizes, aesthetic requirements, and waste tolerance. Here is a general comparison of cost-effectiveness by grade and application.

GradeRelative PriceUsable YieldWaste FactorBest Value For
FAS$$$$$ (100%)83 - 100%0 - 17%Long, wide clear panels
F1F / Select$$$$ (85-90%)83 - 100%0 - 17%One-sided applications
No. 1 Common$$$ (65-70%)67 - 83%17 - 33%Most furniture & cabinets
No. 2 Common$$ (45-55%)50 - 67%33 - 50%Short parts, rustic look
No. 3 Common$ (30-40%)33 - 50%50 - 67%Flooring, character pieces

Pro Tip: The No. 1 Common Sweet Spot

For most furniture and cabinet projects, No. 1 Common (Cabinet Grade) offers the best cost per usable board foot. You pay 30-35% less than FAS but only lose 10-15% in yield. The smaller clear areas are usually more than sufficient for drawer fronts, door panels, face frames, and table components. Reserve FAS for wide, unbroken panels like conference table tops or full-width bookmatched veneers.

How Reclaimed Hardwood Is Graded Differently

Standard NHLA grades were designed for freshly milled lumber. Reclaimed hardwood has a different set of characteristics that require a modified grading approach. Here is how we evaluate and grade reclaimed stock at North Iowa Lumber.

Why Standard Grades Fall Short

Nail Holes: Reclaimed wood almost always contains nail holes from its original use. Under strict NHLA rules, these are defects. But in the reclaimed market, nail holes are expected and often desired for their character. We do not penalize boards for nail holes unless they compromise structural integrity.

Checking & Splits: Minor surface checks and end splits are common in century-old wood. These are typically stable and do not progress further. We evaluate whether checks are structural concerns or purely cosmetic.

Patina & Discoloration: Surface oxidation, weathering, and staining from age are defining features of reclaimed wood — not defects. A board with deep, rich patina may grade poorly under NHLA rules but commands a premium in the reclaimed market.

Worm Tracks & Insect Damage: Surface worm tracking (where insects have carved shallow channels) adds visual texture and is highly sought after for accent walls and furniture. We grade this as a character feature, not a defect, unless it compromises structural capacity.

Our Reclaimed Grading System

Grade A — Premium: Clean, tight grain with minimal nail holes (filled or unfilled). Little to no checking. Rich, even patina. Full thickness with no significant material loss. Suitable for fine furniture, visible architectural features, and high-end projects.

Grade B — Standard: Moderate nail holes, minor checking, some color variation. Structurally sound with good overall appearance. Light surface wear acceptable. The most common grade for general-purpose reclaimed projects.

Grade C — Character: Heavy nail holes, visible checking, worm tracks, mixed patina. May have minor edge damage. Structurally functional but with significant character marks. Ideal for accent walls, rustic furniture, and projects where heavy character is desired.

Grade D — Rustic: Extensive wear, large nail holes, significant checking or splitting, possible thickness variation. Best for decorative applications, non-structural cladding, art projects, and photo backdrops.

CharacteristicGrade AGrade BGrade CGrade D
Nail Holes per BF0 - 22 - 55 - 1010+
CheckingNone to hairlineMinor surfaceModerate surfaceHeavy, may be through
Patina QualityEven, richGood, some variationMixed, variableHeavily weathered
Worm TracksNoneMinimalPresentExtensive
Edge ConditionClean, fullMinor wearSome damageIrregular
Structural IntegrityExcellentGoodAdequateDecorative only
Thickness ConsistencyWithin 1/16"Within 1/8"Within 1/4"Variable
Best ApplicationFine furnitureGeneral projectsAccent featuresDecorative use
Relative Price$$$$ (Premium)$$$ (Standard)$$ (Value)$ (Economy)

Species-Specific Grading Notes

Some hardwood species have special grading considerations under NHLA rules. Here are notes for the species most commonly found in our reclaimed inventory.

White Oak

Graded under standard NHLA rules. Sapwood (white/cream) is considered a defect in FAS and F1F grades — the board must be predominantly heartwood (tan/brown). In No. 1 Common and below, sapwood is permitted. Reclaimed white oak from barn frames is often heartwood-dominant due to original timber selection practices.

Red Oak

Standard NHLA grading applies. Color variation between sapwood (light) and heartwood (pink/red) is more pronounced than in white oak. Mineral streaks (dark lines) are not considered defects but may affect visual appearance. Reclaimed red oak flooring often features rich, dark patina from decades of foot traffic.

American Chestnut

Extremely rare in new production due to the chestnut blight (early 1900s). Essentially all chestnut available today is reclaimed. Grading is adapted — worm holes from the chestnut borer are common and considered character marks rather than defects. Commands premium pricing regardless of technical grade.

Heart Pine (Longleaf)

Reclaimed heart pine is dense, resinous, and rich in color. NHLA grades are rarely applied because virtually all heart pine available is reclaimed. Graded primarily on nail-hole density, checking, and percentage of heartwood vs. sapwood. Old-growth heartwood (tight, dark rings) is significantly more valuable than sapwood.

Hard Maple

Unique grading quirk: white maple (sapwood) is more valuable than heartwood for most applications. FAS White Maple requires the face to be predominantly white sapwood. Reclaimed maple from factory floors and bowling alleys often has a distinctive honey amber patina from age and wear.

Walnut

Graded under standard NHLA rules with one exception: sapwood (white/cream edges) is considered a defect in FAS grade. Steamed walnut (uniform brown color) is graded the same as natural. Reclaimed walnut is uncommon but highly valued — most sources are from old furniture factories and gun stock blanks.

Not sure which grade to order? Send us your project details and we will recommend the most cost-effective grade for your application. We can also send sample boards so you can evaluate the character level before committing to a full order.