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Pallet lumber grades

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In short

Pallet lumber grades limit defects such as knots, wane, splits, decay and slope of grain. The Uniform Standard sets two minimum quality levels, reusable (about PDS Standard grade) and single-use (about PDS Economy), and PDS grades run Select, Premium, Standard, Utility and Economy, often written as a minimum plus better (for example Standard &BTR).

On this page
  1. How pallet grades work
  2. Uniform Standard minimum lumber quality (Table 1)
  3. Grades for recycled pallets
  4. Choosing a grade
  5. How grade shows up on a spec
  6. How palletdesign.ai uses grade

How pallet grades work

Pallet lumber is not graded like construction lumber. Instead, pallet specs use grades defined for pallet parts, based on how many defects a piece may have and how large they can be. There are two related systems:

  1. Uniform Standard minimum quality (Table 1 of the Uniform Standard for Wood Pallets): one level for reusable pallets and one for single-use.
  2. PDS component grades: Select, Premium, Standard, Utility and Economy.

"&BTR" (and better) means the named grade or anything above it. "Standard &BTR" is a common spec line, and older PDS sheets used "Multiple-Use & BTR".

The Uniform Standard's reusable level corresponds roughly to PDS Standard, and its single-use level roughly to PDS Economy.

Uniform Standard minimum lumber quality (Table 1)

Defect Reusable Single-use
Sound knots Up to 1/2 of the cross-section; 2 max-size knots per 6 in Up to 7/8; 1 per half length
Unsound knots and holes Up to 1/4 Up to 1/3
Wane, exposed deckboard faces Up to 1/4 x 2/3 Up to 3/8 x full thickness
Wane, non-exposed deckboard faces Up to 1/3 x 2/3 Up to 1/2 x full thickness
Wane, stringers and blocks Up to 1/3 x 1/2 Up to 5/8 x 2/3
Decay Up to 1/4 Up to 1/4
Splits, deckboards Up to 1/3 of length Full length
Splits, stringers Horizontal under 4 in or 2x width Horizontal under 4 in or 2x width; vertical up to 1/2 length
Slope of grain 1 in 4 1 in 4

These values are from the 2012 edition. Check the current revision before enforcing them.

Additional rules

  • Extra limits apply around notches: no decay within 2 in of the notch ends, and limited wane above the notch.
  • Single-use quality is allowed only if deckboards are at least 5/8 in thick and stringers or blocks at least 1-1/4 in wide.
  • No more than one third of the components may contain wane.
  • Saw mismatch (a step in the surface) is limited to 1/32 in.

Grades for recycled pallets

Used and recycled pallets are sold on different, market-based grades:

  • Premium A
  • Grade #1 (also called A)
  • Grade #2 (also called B)
  • Core

Exact definitions vary by supplier and buyer spec. Buyers also use loose phrases like "pallet grade", "#2 &BTR" and "Utility & Better". If you use these, define them on the RFQ. See recycled lumber and recycled pallets.

Choosing a grade

  • Reusable pallets in closed loops or pools: Standard &BTR or better.
  • One-way export or single-use shipments: Economy may be acceptable if the part sizes meet the single-use minimums above.
  • Appearance-sensitive programs, such as retail display: Premium or Select.
  • Racked or heavy loads: grade affects strength. Specify the grade on the spec so the capacity analysis uses the right values.

Example: can this pallet use single-use quality?

A GMA-style 48 x 40 with 5/8 in deckboards and 1-3/8 in stringers meets the single-use size minimums (deckboards at least 5/8 in, stringers at least 1-1/4 in). The same design with 1/2 in deckboards would not, and would need reusable-quality lumber.

How grade shows up on a spec

A PDS-style lumber block lists each species class with its grade and share, for example "Mixed Eastern Hardwoods: HD Standard &BTR 50%, MD Standard &BTR 25%, LD Standard &BTR 25%". An RFQ should state the minimum grade, the use class (reusable or single-use), and whether mixed grades are acceptable.

How palletdesign.ai uses grade

palletdesign.ai lets you pick premium, standard or economy grade. In the indicative cost estimate, premium multiplies the lumber cost by 1.2 and economy by 0.85, relative to standard. Those multipliers are the engine's default assumptions, not market prices. Grade does not change the engine's indicative capacity check, which uses one conservative bending stress per species, so confirm capacity at your chosen grade with a PDS analysis or test.

Questions

What does Standard &BTR mean on a pallet spec?
Standard grade and better: every piece must meet at least the Standard grade, and higher grades are also acceptable.
What lumber grade is required for a reusable pallet?
The Uniform Standard's reusable quality level, which corresponds roughly to PDS Standard grade. Single-use pallets can use a lower level, roughly PDS Economy.
How much wane is allowed on pallet deckboards?
For reusable pallets, up to 1/4 of the thickness by 2/3 of the width on exposed faces under the 2012 Uniform Standard; single-use allows more.

Sources