Must a Projectile Pallet complete the full 48-hour salt spray?

Answer: First article and annual re-verification run the whole 48 hours. Routine batches may screen at 24 hours and extend if scribe creep appears, with the shortened duration recorded.

Without a salt spray cabinet, how is corrosion judged?

Answer: Check the cut edge for exposed substrate, the fasteners for rust points, the scratches for blistering. Clean results earn a provisional pass only.

Where does the 1.5 times stack factor come from?

Answer: From dynamic amplification in transit. Road freight calls for 1.5, repeated transfers with manual handling push it to 2.0, and static storage runs at 1.2.

How is the sample size set?

Answer: By lot size and inspection level: for 501 to 1200 units at level II, sample 80. Critical defects are zero-tolerance; major and minor run at AQL 1.0 and 2.5.

Projectile Pallet Acceptance: Six Checks and a 48-Hour Salt Spray

Quick answer: Most Projectile Pallet acceptance decisions need no outside lab: four of the six checks close on the receiving dock the same day, provided gauge and limit are pinned down first.

Six Checks on One Sheet
Gauges and Measuring Points
Appearance and Structure: Three Defect Classes
Performance Sampling: Stack, Drop and Cold
Disposition of Nonconforming Units
FAQ

1. Six Checks on One Sheet

An inspection sheet fails because every item sits in one flat list, so the receiver cannot tell what must close today. On a Projectile Pallet the six checks split by origin of the result: documents, gauges, bench tests. The first two close on the dock; bench tests run at first article and batch re-verification only.

Documents decide whether paperwork matches goods. The material certificate must name grade and lot, and the first-article report must carry measured values for the first, middle and last parts; three identical numbers usually mean nothing was measured.

Check	Gauge or record	Method	Accept limit
Dimensional chain	Class II tape, caliper	3 points per side, diagonals	Diagonal gap 3 mm max
Wall thickness	Ball-anvil micrometer	3 points per long side	3.0 mm, plus or minus 0.25
Appearance	500 lux or daylight	One pass at 600 mm	No through cracks
Stack	Weights or ballast	1.5 times load, 24 hours	Deflection 2.5 mm max
Salt spray	Neutral cabinet	5 percent salt, 35 C, 48 hours	Scribe creep 2 mm max
Traceability	Mark and resin ledger	Trace three units	All resolve to a mould

The second column is the one that gets skipped; swap the gauge and the verdict moves by half a tolerance band.

2. Gauges and Measuring Points

A reading you cannot repeat turns inspection into opinion.

Projectile Pallet: olive green case open on a steel bench, egg-crate foam in the lid, six cut compartments below, folding handle

Measure where the load goes, not where the surface is easy to reach. Wall thickness reads at three points per long side, 50 mm in from either end, plus two on the base ribs. Take length at the rim plane, because a jaw pushed into the corner radius slides inward.

Five tools cover the dock:

Class II steel tape, 3 m, for length and diagonals
Vernier caliper, 0.02 mm, for rim and latch seats
Ball-anvil micrometer for curved walls
Feeler gauges, 0.02 to 1.0 mm, for the lid gap
A colour chip for batch shade

Log three values per Projectile Pallet: point, reading, verdict. Drop one and a re-check cannot tell whether part or inspector changed. Keep a sealed first-article sample stamped with the mould number as the reference in any dispute.

3. Appearance and Structure: Three Defect Classes

Appearance calls break down on two phrases: close enough, and it will not affect use. Three classes end that.

Class	Typical sign	Rule	AQL
Critical	Through crack, broken latch seat	One unit rejects the batch	0
Major	Unfused area, void over 3 mm	Reject past the acceptance number	1.0
Minor	Shade drift, flow line, light scuff	Rework or concession	2.5

The classes differ by an order of magnitude in cost. A critical defect stops the line and sends someone to the mould; a major one implicates a single cavity; a minor one is settled in-house.

The structural item worth separating from appearance is lid-to-body fit. Run a 0.2 mm feeler around the perimeter: where it enters, the gasket is under-compressed; where it will not enter but light shows through, the latch will fatigue first. Both distort the salt spray result.

4. Performance Sampling: Stack, Drop and Cold

Bench tests run twice: first article from a new mould, and three units per batch. Order matters: stack, drop, cold.

Projectile Pallet: olive green case on bare concrete, four latches on the long side, a round valve cap at right

Stack at 1.5 times the rated load for 24 hours. A Projectile Pallet rated at 45 kg per layer is pressed at 67.5 kg, then left two hours before the base centre is measured. Two and a half millimetres or less passes; measuring straight away counts elastic recovery as permanent set.

Drop from 1.2 m, once on each of six faces and once on three edges. Two things are read afterwards: whether the latches close, and whether the joint has shifted.

Cold comes last because it changes toughness. Four hours at minus 25 C, then a drop within 30 seconds, since the material warms quickly and a room-temperature drop measures something else.

5. Disposition of Nonconforming Units

A failed verdict is only the start; disposition decides the route: rework, screening, concession.

Rework covers repairable items such as shade, offset labels and flash. The re-check must repeat the original scope rather than the fixed item, because a second oven pass often introduces fresh distortion.

Screening suits uneven distribution. When wall thickness falls below the lower limit, full inspection separates the good units at a cost in labour. Screened units get a new batch number; mixing them into the original lot breaks the trace.

Concession needs a written deviation permit naming the item, quantity, permitted use and responsible party. Concessioned Projectile Pallet units are downgraded and kept off the main assembly line.

Conclusion

Acceptance of a Projectile Pallet is measured not by the length of the sheet but by whether all six checks end in a number. Documents cover origin, gauges the dock, bench tests the batch. Settle the measuring points before the first delivery, and every later Projectile Pallet batch is argued with data.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.