Why is the lid boss fixed at 8 mm instead of higher?

A: At 10 mm a Stackable Military Storage Case leaves its lid unseated with the four latches short of travel and the gasket below 24 % compression; 8 mm keeps slip inside 1.2 mm after 5 layers over 24 h without tilting the mating line.

Why is the recess clearance 0.7 mm?

A: It leaves room for assembly tolerance and creep together. At 1.0 mm, five-layer slip crosses 1.2 mm; below 0.4 mm, a shrinkage shift makes the recess refuse the boss, and mallet work whitens the wall and distorts the datum.

Why 5 layers over 24 h rather than 3?

A: The first 2 h of a Stackable Military Storage Case bed the faces in and the curve flattens past 8 h, so three tiers cannot show the late slope.

Do the off-centre recheck and the stack test measure the same thing?

A: These are separate checks. Stacking records how far tiers drift over 5 layers and 24 h; the off-centre recheck records whether 3.2 kN applied to one side shears a boss. Both columns must close before a batch is released.

Does gasket compression relate to interlayer slip?

A: They are separate readings tied to the same lid fit. A boss made too tall keeps the four 435 N latches from seating, the gasket misses 24 % compression, and a tilted lid pushes the stack load to one side, so slip grows with it; closing has to be checked with stacking.

Stackable Military Storage Case

Quick answer: A Stackable Military Storage Case keeps slip under 1.2 mm across 5 layers over 24 h, set by an 8 mm lid boss and 0.7 mm recess clearance.

Lid-top boss height of the Stackable Military Storage Case
Fit clearance of the base recesses
Interlayer slip readings by stack tier
Compression verdict under off-centre load
Boss scrap limit for stacking batches
FAQ

1. Lid-top boss height of the Stackable Military Storage Case

A Stackable Military Storage Case is laid out on a 660×470×290 mm outer envelope with a 590×405×220 mm inner cavity, both walls at 5.0 mm. Four solid bosses stand on the lid, 8 mm high, matched to recesses in the four base feet; stacked, the upper case sits on the lower one's bosses and the vertical load runs down through these four pairs.

Eight millimetres came from repeated trials: at 6 mm the recess grips too shallowly and tiers shift after five layers, while at 10 mm the lid is propped open, the four latches cannot seat, and the gasket misses 24 % compression. JUNZHIJIA checks all four bosses on the first article and holds the spread under 0.15 mm. The 8.0 kg empty weight cross-checks wall and boss, and the 18 kg load is shared among four side walls and base ribs, never taken sideways by a boss.

Boss height grade	Recess grip	Stack verdict
6 mm	shallow	slip exceeds limit after 5 layers
8 mm	seated	slip within 1.2 mm after 24 h
10 mm	lid propped	latch travel short, scrap

2. Fit clearance of the base recesses

Each of the four feet of a Stackable Military Storage Case carries a recess with 0.7 mm single-side clearance. That allowance absorbs assembly tolerance and long-term creep: at 1.0 mm, five-layer slip crosses 1.2 mm; under 0.4 mm, a shrinkage shift makes the recess refuse the boss and assembly ends with a copper mallet and a whitened datum wall.

Stackable Military Storage Case two large olive closed shells stacked on a pallet, multiple latches and end handles, worker in khaki at right, cartons behind

Recess walls use a 0.5° draft with mouth flare inside 0.05 mm, and a feeler gauge logs all four corners to 0.05 mm on the sheet shared with boss height. Lid foam swells with humidity; folding it into fit readings would make a Stackable Military Storage Case measure differently a week later, so foam thickness is filed apart from every scrap rule.

3. Interlayer slip readings by stack tier

The Stackable Military Storage Case is stacked 5 layers for 24 h, each tier closed with 18 kg ballast and four latches, with no shims between. Two adjacent cases are measured for horizontal shift along the long and short edges, logged tier by tier to 0.01 mm on a dial indicator; first and last readings after 24 h give interlayer slip, accepted at 1.2 mm or less.

Slip moves quickly in the first 2 h while faces bed in, then flattens past 8 h, so closure depends on the last 16 h of slope. Five layers carry margin: tier four is flat and tier five confirms an off-centre load stops growing; a tier-five reading 0.10 mm above tier four is treated as root creep and the batch stays in the hold area.

Stack tier	Long-edge slip	Cumulative interlayer slip
Tier 1	datum	0 mm
Tier 3	+0.5 mm	0.5 mm
Tier 5	+1.1 mm	1.1 mm

Every recheck uses the same indicator and the same inspector; swap either and the datum is re-established.

4. Compression verdict under off-centre load

Cases that pass stacking go onto the drop rig at 1.2 m with 18 kg ballast and four latches, each of the six faces landing once from the base upward. Recesses are not touched afterwards; clearance is re-measured first. A Stackable Military Storage Case takes a single drop sequence, no second pass — a second drop whitens the boss root first and later readings are damage, not springback.

Stackable Military Storage Case three olive long shells stacked on steel racking, top one open with plain lid panel, others closed with corner guards

The off-centre check presses 3.2 kN onto one side of the top tier, watching for a sheared boss or whitened recess wall; no collapse under 3.2 kN is the hard line. Even inside 1.2 mm, a whitened boss root says the load rode on friction rather than engagement, and the piece is rejected. A 4300-cycle open-close run follows the drop on the Stackable Military Storage Case, with boss height measured every 500 cycles and any fall below 7.90 mm logged.

Slip value	After stacking	After off-centre recheck
≤0.8 mm	closes firmly	still closed
0.8–1.2 mm	acceptance edge	check the boss mark
>1.2 mm	scrap	does not enter recheck

5. Boss scrap limit for stacking batches

Put four readings together and the Stackable Military Storage Case has three scrap lines: boss spread above 0.15 mm, recess clearance more than 0.10 mm off 0.7 mm, or slip above 1.2 mm after 5 layers over 24 h with compression failing 3.2 kN. Any one sends the batch back to the tool. Selective pairing can assemble one passing case. The same mould bias follows into the next batch though. JUNZHIJIA does not accept pairing as a process step. Scrap is judged by batch, not by piece: the four bosses from one slide set are judged together, and one out-of-line boss sends all four from that shot back.

At batch release, boss height, recess clearance and five-layer slip are registered side by side. Two gaskets sit in the lid groove at 24 % compression with groove depth back-calculated from cord diameter, and spray and immersion run in the IP67 order while the record only answers whether the lid let water in, with no certificate number or grade verdict.

Conclusion

Whether a Stackable Military Storage Case can be built up tier by tier depends first on the 8 mm boss and the 0.7 mm recess clearance, then on slip holding within 1.2 mm after 5 layers over 24 h and compression surviving 3.2 kN. The drop recheck, 4300 open-close cycles and two gaskets at 24 % compression lock that fit chain into the batch. Registering the three figures side by side gives stacking consistency a paper trail.