A long, parallel beam of wood (typically 48 inches for GMA pallets) running the length of a stringer pallet to support the deck.
Detailed Definition
Stringers are the continuous beams sandwiched between the top and bottom decks of a stringer pallet. Most stringer pallets have three, one along each edge and one in the middle, though heavy-duty designs may use more. Stringers are commonly solid sawn lumber set on edge, and on a 48 x 40 pallet they run the 48-inch direction. They are often cut with notches so forks can enter from the sides as well as the ends, creating a partial four-way pallet.
Stringer sizes and notches
Stringer size is chosen for the load and support conditions: taller and thicker stringers carry more load when the pallet spans rack beams or sits on forks. Notches cut into the bottom edge let forklift tines enter from the side, but they remove wood where the stringer is most stressed, so a notched stringer pallet has lower capacity from the notched sides. Notch size and location vary by specification.
Common stringer damage
Stringers often crack at the notches, split along nail lines, or break in the middle when a pallet is dropped or overloaded. Recyclers repair damaged stringers by replacing them or by adding a companion stringer or metal plate beside the damaged one. How much repair is acceptable is a matter of the buyer's specification and the recycler's grading, so state your limits in the order, for example the maximum number of companion stringers or plates allowed per pallet.
Stringer orientation in rack
- Stringers should usually span across the rack beams, front to back.
- If stringers run parallel to the beams, the pallet is supported only at its ends.
- Check that a pallet's racked capacity matches the orientation actually used.
Related Glossary Terms
Frequently Asked Questions
How many stringers does a pallet need?
Three is the most common arrangement for 48 x 40 and similar stringer pallets: one on each edge and one in the center. Heavier loads, wider pallets or demanding rack spans may call for four or more, or for larger stringers. The right number comes from the pallet design for your load, footprint and support conditions, which a supplier can work out with tools such as the NWPCA Pallet Design System.
Can a cracked stringer be repaired?
Often, yes. Recyclers commonly fix damaged stringers by fastening a companion stringer alongside the cracked one or by applying metal stringer plates. Badly broken stringers are usually replaced outright. Repaired pallets can perform well, but heavily repaired units may not suit every application, especially high rack or automation. Agree with your supplier on how many repairs per pallet you will accept.