Light, medium or heavy duty: matching shelving to what you actually store
Duty ratings are often quoted as a single number per layer. The number that decides your specification is the one you have not measured yet.
Shelving ranges are usually split into light, medium and heavy duty, and the split is about the load per shelf and the way goods are put on it. A 100 kg shelf loaded by hand from a step ladder is a different product from a 300 kg shelf loaded by a pallet truck.
Start from the heaviest single item
The average weight of stock on a shelf tells you very little. What matters is the heaviest thing that will ever sit on it, because one heavy item in the middle of a shelf can exceed a rating that the rest of the stock never approaches. Add the container: a steel tote or a wooden crate can weigh a fifth of the contents.
Then the loading method
- Hand-loaded, small items, archives, retail backroom: light duty, typically 100–250 kg per layer.
- Cartons and totes handled daily, workshop spares: medium duty, 250–300 kg per layer.
- Dense industrial stock, stacked pallets, tooling: heavy duty from 300 kg per layer upward, or racking rather than shelving.
A shelf rated at 250 kg per layer in a stockroom where staff climb the frame to reach the top level is not a 250 kg shelf in practice. If access requires climbing, specify a proper ladder or a lower top level instead.
Where light shelving fails first
Not in the shelf plate, but at the beam-to-upright connection and at the feet. Boltless systems rely on the connector and the mallet fit; a unit that is repeatedly dismantled and rebuilt loses that fit. If the layout will change regularly, buy a system with a positive lock rather than a friction fit, and expect to replace the connectors, not the whole unit.
