Is a 90 kg pallet still an ista 3e case job?

A: Yes. The 68 kg threshold is a starting point. If the load goes on forks and three tiers high, the load path is pallet-level.

Why is one pallet enough as a sample?

A: The unit load is the article shipped. The eighteen cases inside come from one mould and one lot, and run all six steps without substitution.

Is 4.5 kN just case weight times tiers?

A: It is gross load mass times the tiers above: two pallets at 230 kg rest on the bottom one, and 460 kg × 9.81 gives 4.5 kN.

Does a broken pallet fail the load?

A: Yes. A snapped deckboard or a stringer that loses its nails fails the run, because the load path is gone before the cases are inspected.

Ista 3e Case: ISTA 3E for Cases

Quick answer: An ista 3e case run qualifies one whole palletized load above 68 kg: six steps, a 200 mm edge drop, 0.5 Grms of vibration and 4.5 kN of stacking.

What the 68 kg Threshold Decides
Six Steps on a 1200 × 1000 mm Pallet
Where the Pallet Takes the Hit
Thirty Minutes at 0.5 Grms
Turning Three Tiers into 4.5 kN
FAQ

1. What the 68 kg Threshold Decides

Eighteen cases at 12 kg each, stacked three high on a 14 kg timber pallet, make a 230 kg unit load. That load is the subject of ISTA 3E. A single case cannot answer for how a stack behaves on forks or at a dock plate.

The 68 kg line marks where handling turns mechanical. Below it a parcel is tipped down a chute and pressed against cartons, so energy lands on corners; above it a forklift and pallet carry the freight, so energy lands on the pallet edge and the bottom tier.

A pallet-level run reports whether the stack survives the chain, not how far one case can fall. That changes how a report is read: a bottom corner may crack 3 mm without breaching the wall and the load still passes, while an unmarked case rides on a snapped deckboard and the load fails.

Unit load build	Specification	Note
Case footprint	500 × 400 × 300 mm	12 kg each, 4 mm wall
Cases per tier	6	400 mm edge along 1200 mm
Tiers	3	18 cases
Pallet	1200 × 1000 mm, 14 kg	22 mm deckboards, 3 stringers
Gross mass	230 kg	Cases, pallet and straps
Strapping	16 mm PP, 1.1 kN	2 vertical, 2 horizontal

2. Six Steps on a 1200 × 1000 mm Pallet

Each step enlarges a defect left by the one before; the values below are typical for 3E and the current edition governs. S1 conditions the load to an ISO 2233 atmosphere and measures the outline, where anything beyond 0.3% sends the batch back to its material record. S2 drives the 230 kg stack into a barrier at 1.8 m/s. S3 lifts one bottom edge 200 mm and releases it. S4 runs 0.5 Grms vertically for 30 min. S5 repeats the edge drop. S6 loads the top with 4.5 kN for 24 h.

Ista 3e case seen from above with the lid open, black base foam cut into square pockets holding red and black leads

Step	Typical parameter	Pass line
S1 Conditioning	ISO 2233 atmosphere	Outline change ≤ 0.3%
S2 Incline impact	1.8 m/s into barrier	Corner intact, strap slip ≤ 10 mm
S3 Edge drop, first	Lift 200 mm	No through-crack at corners
S4 Random vibration	0.5 Grms, 30 min	Case shift ≤ 8 mm, film intact
S5 Edge drop, second	Lift 200 mm	Edge crush ≤ 3 mm
S6 Stacking	4.5 kN, 24 h	Height change ≤ 2%

Half the steps load the pallet directly; once it gives way, the stack loses its load path and no wall thickness recovers it.

The vibration segment sits between the two drops on purpose. A strap that has slipped 10 mm has already moved the upper tiers off their support, so the second landing turns an 8 mm shift into visible corner crush.

3. Where the Pallet Takes the Hit

In this example the impact segment has two numbers: 1.8 m/s and 0.12 s. A 230 kg load that stops from 1.8 m/s in 0.12 s averages 15 m/s², with a peak more than double that. The force runs through the stringer, the six bottom cases, then the straps. A 16 mm strap at 1.1 kN holds the stack; halve the width and slip grows from 10 mm to 25 mm while the pallet corner splits.

The edge drop loads the stack differently. Lifting one bottom edge 200 mm pivots the load about the far edge, so 230 kg lands on a single line, roughly 2.3 kN/m over a 1.0 m pallet length, exactly where the case rim meets the deckboard.

4. Thirty Minutes at 0.5 Grms

Vibration uses one typical level and direction: 0.5 Grms vertical for 30 min. That is about 4.9 m/s² RMS, above what a highway leg produces, so 800 km of road is compressed into half an hour. The table measures 3 m × 2 m and a 100 mm rail stops lateral walk.

Ista 3e case open on a steel bench, foam bays labelled PROBES, CABLES and PANEL, instrument racks and a sunset window behind

Three things get checked afterwards: whether the stretch film loosened, whether upper cases shifted past 8 mm, and whether deckboard nails backed out.

The duration has a floor and a ceiling: under 20 min the upper tier has not settled; past 60 min, creep in a PP case swallows real displacement.

5. Turning Three Tiers into 4.5 kN

Stacking is arithmetic. The bottom load carries the two tiers above it: 2 × 230 kg × 9.81 gives 4.5 kN. Spread over 1200 × 1000 mm that is 3.75 kPa, yet a bottom wall sees it as local load at mid-height, and that is what buckles.

Hold 24 h, then measure height. A 1050 mm stack that loses 21 mm has dropped 2%, the usual limit; past it the lid gap opens in the next handling step.

Unpacking check	Pass line	Usual location
Corner crack	≤ 3 mm, not through	Four bottom corners
Edge crush	≤ 3 mm deep	The dropped long edge
Lid gap	≤ 1 mm, even along length	Front lid centre
Latch return	All seated within 5 s	Two front draw latches
Liner shift	≤ 2 mm, still seated	Foam against wall

Finish the checks within 1 h, because a case relaxes and a crack closes as it does. Photograph four sides of the load, one with the lid open and one per case, at least 24 frames for 18 cases.

Conclusion

An ista 3e case programme is a pallet-level argument: 230 kg on a 1200 × 1000 mm pallet, six steps, a 200 mm edge drop, 0.5 Grms for 30 min and 4.5 kN held for 24 h. Confirm the outbound form first, and every figure will match the dock.

This article covers case-side specifications only and does not address any handling, loading or use of the contents.