Inspect the crate, not only the goods
A pre-shipment inspection usually concentrates on the goods, because the goods are what the buyer paid for. The crate is treated as packaging, and packaging is assumed to be a solved problem.
It is not. The failures that turn into claims at destination are mostly built in before the crate is closed: a brace that does not reach the part, a base that was sized for a lighter machine, a joint that was set for a thinner panel. None of them are visible from outside, and all of them are obvious in the ten minutes before the lid goes on.
The inspection below is ordered that way: inside first, while you can still change something, then outside, then the paperwork.
Inside the box, before the lid goes on
Check these four things in this order. Each one makes the next one meaningless if it fails.
- The part is held, not merely surrounded. Push it. If it moves, the blocking is decorative, and it will move further over a sea voyage than it moves in the yard.
- The load reaches the base. Follow the weight down through the blocking to the base members. If the path runs through a panel rather than a member, the panel is carrying a point load it was not chosen for.
- Nothing hard touches a finished surface. Every contact between the part and the crate should be through a soft interface. Metal on metal, or metal on painted face, is a scratch waiting for vibration.
- The fastenings are at the spacing the design assumes. On a buckled or steel-edged box the joint pattern is set by the machine; check that the pattern is continuous along the loaded edges rather than clustered where it was convenient.
Outside the box, after closing
The squareness check deserves a note. A crate that is slightly out of square will still close, and will still pass a glance. It becomes a problem when the box is stacked or when a reusable crate is reassembled, because the error compounds with each cycle.
| Check | Pass condition |
|---|---|
| Squareness | Diagonals within the same tolerance across the box |
| Edge condition | Edge profile continuous, no gaps at corners |
| Base and skids | Flat, parallel, clear fork entry |
| Panel faces | No delamination, no unsupported spans |
| Marks | Consignee, destination, package number, gross weight |
Who inspects, and when
The most useful split is between the inspection that happens at the factory and the one that happens at the dock.
At the factory, the person who can still change something should inspect: the part fit, the blocking, the base and the joint pattern. At the dock, the check is shorter and narrower: external condition, marks, count, and whether the crate still sits flat after handling.
If a third-party inspector is involved, give them the crate drawing as well as the part drawing. An inspector working only from the part drawing will pass a crate that meets the part and fails the route.
Where the repeatability comes from
Inspection catches variability; it does not remove it. The variability that matters most is in the joint, because the joint is what holds the geometry of the box.
Our line builds plywood boxes from 5 to 12 mm with three core machines: a buckle machine that fastens panel joints at programmed positions at 30 to 60 fastenings per minute, a steel-edge forming machine that rolls the edge profile to length, and a hydraulic press that presses the formed edge onto the panel. Three machines, one matched line. When the joint is set by the machine, the inspection question changes from "did the operator get it right" to "was the setting correct", which is a question you can answer once instead of ten thousand times.
What to send us
If you are writing an inspection checklist for your own crates, send the crate drawing, the joint pattern and the route. We can tell you which checks have to happen before closing and which panel tolerances the joint pattern depends on.