Height variance
Shuttle and AS/RS systems index on height. A pallet half an inch taller than expected can foul a rail or mis-seat in a bay. This is the failure we see most and the one least often specified against.
Specification · 25 February 2025
Automated warehouses and the quarter-inch that stops a line
In short
Automated storage and handling systems fail on dimensional variance, protruding fasteners and bottom-deck geometry — not on appearance. A pallet that a human operator would handle without a second thought can stop a conveyor line, and the cost of that stoppage dwarfs any saving on the pallet. Specifying for automation means height sorting, shiner inspection, consistent bottom-board placement, and frequently block construction.
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What actually stops the line
Bottom-deck geometry
Conveyor rollers and chains engage the bottom deck. Missing, shifted or non-chamfered bottom boards cause hang-ups even when the top of the pallet is perfect.
Shiners
A protruding nail catches a chain, a belt, or a photo-eye bracket. On an automated line this is a stoppage; on a manual dock it is an annoyance. Same pallet, very different cost.
Loose or cracked boards
A board that flexes under a roller can trip a jam sensor without actually jamming, which is worse — intermittent faults take far longer to diagnose than hard ones.
Footprint variance
Squaring devices have a capture range. Outside it, the pallet is rejected and manually handled, which defeats the automation.
Notch geometry
Stringer notches vary between builds and repairs. Systems that engage the pallet from the side frequently prefer block construction for exactly this reason.
What to specify
| Parameter | Typical automation requirement | Standard recycled stock |
|---|---|---|
| Footprint tolerance | ±1/4 in | ±1/4 to ±1/2 in |
| Height tolerance | ±1/4 in, sorted | Not controlled unless requested |
| Bottom deck boards | All present, chamfered, consistent placement | Present, placement varies |
| Shiners | Zero, inspected | Zero (our standard) — verify with your supplier |
| Construction | Block preferred; jig-built stringer acceptable | Mixed |
| Board thickness | Consistent within a lot | Varies with repair history |
Note that none of these rows mentions colour, uniformity or cosmetic grade. Buying A grade for an automated facility because A grade is "the best" is a common and expensive misunderstanding — A grade describes appearance and repair history, and an automated system cannot see either.
How we supply it
Automation orders come off a separate line. Units are height-sorted with a gauge rather than by eye, bottom decks are inspected specifically for placement and chamfer, and a dedicated final pass checks for shiners on both faces. Where tolerance requirements are tight, we recommend jig-built remanufactured units or block construction rather than straight recycled stock, because a jig holds dimension and a pile of recovered cores does not.
Appendix: the data behind this
Every piece on this site closes with the slice of our operating record that bears on what it argues. The full record is published at /resources/operating-record.
Posted criteria, including the automation line
Note that the automotive and automation block says nothing about appearance. It is entirely about tolerance, fasteners and documentation.
Universal — every grade
- No cracked or split stringer longer than 3 in on any load-bearing member.
- No protruding or shiner nails on any deck surface, top or bottom.
- No metal plates. We do not apply them and we do not accept them inbound.
- No mould bloom, chemical staining, odour, pest damage or exit holes.
- Deck gaps within 3.5 in for fork and conveyor compatibility.
- Moisture content below 19% for stock going to indoor storage or export.
- No bark anywhere on stock destined for export.
Additional for A / #1
- No plugged stringers. No companion stringers.
- All seven top deck boards present and full width.
- Five bottom deck boards present, chamfered.
- Uniform colour across the deck — no heavily weathered board against a fresh one.
- No residue, no labels, no staining of any kind.
Additional for automotive and automation stock
- Zero shiners, inspected on both faces as a separate final pass.
- Height sorted to ±1/4 in with a gauge, not by eye.
- Footprint tolerance ±1/4 in — jig-built or remanufactured stock only.
- Build date, jig number and grade recorded per lot and supplied with the shipment.