Maximum working load
Maximum working load is the largest payload a pallet is allowed to carry in a specific load and support configuration, as defined in ISO 8611-3. Unlike the nominal load, it reflects how the load sits on the pallet and how the pallet is supported, so one pallet has different maximum working loads for racking, forklift handling and floor stacking.
Also called MWL, working load
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How it differs from other ratings
| Rating | Depends on your load and support? |
|---|---|
| Nominal load | no, standard test setup |
| Maximum working load | yes, specific load type and support |
| Safe working load | yes, stated per condition |
What changes the maximum working load
- Support condition: rack beams, forklift tines, floor, stack height
- Load type: uniform cartons, soft bags, rigid line loads, drums, point loads
- Span: a wider rack span lowers the rating
- Duration and environment: long-term loads cause creep; wet service weakens wood
How to use it in an RFQ
State the real conditions rather than asking for a single capacity number: maximum and average load, how the load sits (uniform, drums, bags), rack type and beam span, forklift or pallet jack, and stack height. The manufacturer then rates the design for those conditions through a PDS analysis or a test to ISO 8611 or ASTM D1185. See how to write a pallet RFQ and ISO 8611.
Questions
- Is maximum working load higher than nominal load?
- It can be higher or lower. It depends on how the actual load and supports compare with the idealized test setup.
Related
- ISO 8611: pallet load testing, nominal and working loadsISO 8611 sets test methods and load ratings for flat pallets: nominal load is a comparison rating, maximum working load is the allowed payload per support case.
- Nominal loadNominal load is the ISO 8611 comparison rating from a standard rigid-beam test. It is used to compare pallets, not the payload a pallet can carry in service.
- Safe working loadSafe working load (SWL) is the rated load for a pallet in a stated support condition, with a safety margin. It is not the breaking load and varies by condition.
- Pallet load capacity: safe load, support conditions and ratingsPallet load capacity depends on support: floor, stacked, forklift or racked. How safe load differs from breaking load, and how ratings are set.
- Methyl bromideMethyl bromide (MB) is an ISPM 15 fumigant for wood pallets. It is being phased out and some countries ban it, so most export pallets are heat treated.
- MIBANTMIBANT (Morgan Impact Bend Angle Nail Tester) rates pallet nail stiffness as a bend angle under ASTM F680. A lower angle means a stiffer, better nail.