Guides / Grades and Specs

Pre-Shipment Grading That Prevents Hardwood Grade Disputes: A Checklist for Mills

February 17, 2027

Most hardwood grade disputes start with two honest graders reading the same board differently, or with a contract that never said which rule applied. A pre-shipment grading check closes both gaps. Agree the rule and the face in writing, pull a sample from across the load, grade the sample boards the way the rule book does, record the result and fix problems before the container is sealed. This guide is for mills, yards and exporters. It covers the steps, a worked grading example, when to bring in an NHLA inspector and how the published sales code treats a shipment that misses grade.

This is general information as of October 2026. I could not open the current NHLA rule book, so the grading mechanics and the sales code figures come from a Purdue Extension publication that summarizes the 1998 edition. Treat the numbers as a starting point and check the current rules your contract names.

Why disputes start

Purdue Extension notes that the NHLA rules were first published in 1898 to help sellers and buyers establish a basis on which lumber at the producer’s location could be sold without examination by the buyer. A buyer abroad who has not examined the lumber relies on exactly that: your grade, read the way the rule book reads it. The same publication says the grade rules are mostly mathematical, and the subjective part is deciding what is and is not a defect. That is where two graders disagree, so the check needs a written rule, a named face and a record of what was seen. Our guide to NHLA grades explains the grades themselves.

Step 1: Write the rule into the order

Before grading anything, make sure the order or confirmation says:

• Which rules. NHLA Rules for the Measurement and Inspection of Hardwood and Cypress, with the edition year. Purdue notes the sales code section of the rules binds buyer and seller only when the contract states that it governs.
• Which grade and which face. Most grades are set from the poorer face. FAS 1-face and Select need one face to grade FAS and the reverse No.1 Common, so the order must say which grade it is.
• Species exceptions. Walnut and butternut have their own limits. Purdue gives walnut FAS a minimum width of 5 in against 6 in standard, and admits pieces 6 and 7 ft long against the standard 8 ft. Say whether the order follows the species rule.
• Thickness and surfacing. AHEC says rough kiln dried lumber 3/8 in to 1 3/4 in thick may be 1/16 in scant, and 2 in and thicker 1/8 in scant. Put the tolerance you apply in the order.
• Tally basis and moisture. Grade is only part of what the buyer checks. See our guides on the tally sheet and on moisture meters.

Step 2: Pull a sample that means something

The sales code and the rule book do not give a public sample size that I could open, so there is no number to quote. Decide yours in advance and write it down. A workable method:

1. List every item on the order (species, grade, thickness, drying).
2. For each item pick bundles from different positions in the stack: top, middle, bottom, front and back of the lot.
3. From each chosen bundle pull boards from different layers, not the top layer only.
4. Grade each board on both faces, and record the poorer result.
5. Keep the pulled boards together with the bundle tag number so the result ties back to the tally.

A buyer’s inspector will not pick your best bundles, so do not pick them either. If you photograph the sample, follow the habits in our guide to photographing lumber lots.

Step 3: Grade the board the way the book does

Purdue’s steps for one board are:

1. Identify the species.
2. Find the surface measure (SM): width in inches times length in feet, divided by 12, rounded to the nearest whole number, with half values alternating up and down.
3. Find the poor face.
4. Look up the number of cuttings allowed. For FAS it is SM divided by 4, dropping fractions.
5. Check the minimum cutting size. For FAS it is 4 in by 5 ft or 3 in by 7 ft.
6. Calculate the cutting units needed: SM times the required fraction of twelfths. FAS needs 10/12, so 83 1/3% of the board is in clear face cuttings.
7. Lay out the cuttings and count the units, where a cutting’s units are its width in inches times its length in feet. If the total meets the requirement, the board makes the grade. If it does not, try the next lower grade.

Two worked examples from the Purdue publication, using its numbers:

	12 in x 12 ft board, FAS	6 in x 8 ft board, FAS
Surface measure	12	4
Cuttings allowed	12 / 4 = 3	4 / 4 = 1
Units on the board	12 x 12 = 144	4 x 12 = 48
Units needed (10/12)	12 x 10 = 120	4 x 10 = 40
Example cutting	120 or more units in up to 3 cuttings of at least 4 in x 5 ft	One cutting of 6 in x 7 ft = 42 units
Result	Makes FAS if the cuttings reach 120 units	42 is at least 40, so it makes FAS

Mills that grade every day do this by eye with a scale stick, not on paper, but the paper method is the one an inspector can reproduce. If a sampled board lands within a unit or two of the limit, call it the lower grade. A buyer’s grader will.

Step 4: Check what grade does not cover

Grade does not say everything about the boards. Check on the same sample:

• Thickness and width against the order, with the scant tolerance you agreed.
• Moisture, at the placement your contract or the buyer will use.
• Sticker stain, end checks, warp and mold, which affect appearance and use whether or not they change the grade.
• Species, since a stray board of another wood is a claim by itself.
• Tag numbers against the tally, so a bundle is not labeled with another bundle’s number.

Who should do the grading

Your own trained grader is the usual first line. Purdue notes that grading short courses of about three days, run with the NHLA, teach the rules, but the course does not build the speed needed in production. For a second opinion NHLA lists National Inspectors, described as experienced, certified professionals, with a flat fee of $920 per day for members and $1,380 per day for non-members in the US and Canada. The page lists expedited service for extra fees and travel costs for work outside the inspector’s area, and shows no date, so ask for current terms. In Purdue’s 1998 summary, the NHLA inspector provides a certificate with information about the parcel and NHLA guarantees its accuracy.

Three other NHLA programs are sometimes confused with a grade check:

• Facility Grade certification is described by NHLA as a voluntary quality assurance program for members with independent third-party verification of lumber grading.
• Kiln Drying certification validates your drying process and documentation. NHLA says it achieves the same goals as the APHIS phytosanitary certificate at lower cost for exporters. It is not a grade inspection.
• Strap and Seal is a financial guarantee on inspected, sealed packages. NHLA says it is available for domestic shipments only.

And the USDA export handbook says phytosanitary certificates are not certifications of grade or quality. Our guide on phytosanitary and fumigation rules covers that paper.

How a missed grade is judged

Purdue summarizes the sales code dispute steps this way, for a contract that adopts the code and a national inspection as the basis:

1. The buyer has 14 days from receipt to file a claim with the shipper, and the lumber must stay intact. Surfacing, trimming, ripping or drying it forfeits the claim.
2. If more than 20% of the footage ordered does not meet the order, the buyer can reject the whole shipment and be reimbursed for freight paid, and the supplier pays for the inspection up to a stated labor cap.
3. If at least 80% is in line with the invoice, the money value of the lumber is calculated at invoice prices and recognized prices for anything not on the invoice.
4. If the inspected value is within 4% of the invoice, the buyer loses the claim, accepts the lumber and pays the invoice.
5. If the difference is more than 4%, the seller loses the claim and pays for the inspection.

A made-up example of steps 4 and 5: an invoice of $12,000 and an inspected value of $11,600 is a 3.3% gap, so the claim fails. An inspected value of $11,400 is a 5.0% gap, so the seller loses the claim and pays for the inspection. Real shipments are complicated by mixed grades and prices, which is why the check before shipping matters. Our guide to lumber quality claims shows the process from the buyer’s side.

Use the figures as a design target. If your internal check shows a sample more than a few percent below grade, regrade or sort the lot, tell the buyer and offer a price adjustment before it ships. A disclosed deviation is a negotiation. An undisclosed one is a claim.

Record and send

• Grade check sheet per item: date, who graded, the rule and edition, bundles and boards sampled, the grade found for each board and the poorer face noted.
• Photos of the sample boards with tags, as in our guide on photographing lumber lots.
• Tally and the quote that the shipment follows, with the same species names and units.
• Send a summary to the buyer before the ship arrives, and keep the full record with the shipping papers for as long as your contract or the claim window requires.

Next step

If you sell hardwood lumber and want requests from buyers whose species, grade and thickness fit your stock, register your mill or yard. Tell us the grading rule you use, your drying and tally basis and whether you can supply a grade check record with each shipment. We pass a buyer’s spec to you only when it fits. Each request goes to 3 suppliers at most and the buyer deals with you directly. We reply within 24 business hours, and we make no promise of orders.

Sources

• Purdue Extension, Quality Control in Lumber Purchasing: Hardwood Lumber Grades (FNR-130)
• NHLA, Inspection services
• NHLA, Certification programs
• AHEC, board feet, tally and kiln dried measurement
• USDA Foreign Agricultural Service, A Guide to Exporting Solid Wood Products, Agricultural Handbook 662 (revised January 2002)

Frequently asked questions

Keep reading

• End Sealing Hardwood Lumber: What It Prevents, Which Coating and When It Pays
• Powderpost Beetles in Hardwood Lumber: Which Boards Are at Risk and What to Ask