Is a thicker wall always better on an explosive storage case?

Answer: No. Between 4.0 and 4.5 mm stiffness and mass stay balanced; beyond that weight climbs faster than strength.

Can the cavity be calculated by subtracting two walls from the envelope?

Answer: No. Ribs, radii and draft take another 8 to 12 mm, so the subtraction oversizes the cavity.

Is a resistance band enough on its own?

Answer: No. Voltage and probe locations must sit beside it, or two labs disagree by orders of magnitude.

Do more compartments help?

Answer: Past six, dividers eat a tenth of usable volume and add handling steps, so crews pull the extras out.

Which number settles latch strength?

Answer: Split it into holding force, hinge pins and hole diameter. Merging them hides the failure that matters.

Explosive Storage Case Specifications: Size, Wall and Load

Quick answer: Five numbers decide an explosive storage case: envelope size, wall thickness, rated load, surface resistance and catch force. Fix the loaded weight first, the cavity second, then close the load gap with wall and ribs.

Explosive Storage Case Specifications Start With Five Numbers
Size and Compartments Must Follow the Contents
Wall Thickness Against Rated Load
Static and Flame Clauses for the Contract
Latch Strength and Carry Hardware
FAQ

1. Explosive Storage Case Specifications Start With Five Numbers

A specification for an explosive storage case runs to pages, yet five numbers decide it: envelope size, wall thickness, rated load, surface resistance and catch force. They pull against each other, so the job is choosing which to fix first.

Item	Typical band	How it is judged
Envelope	400 × 300 × 180 mm	Calipers, 3 points
Nominal wall	3.0 to 4.5 mm	Ultrasonic gauge, nine points
Rated load	20 to 30 kg	Uniform load, 24 hours
Surface resistance	10⁶ to 10⁹ ohms	500 V, three probes
Catch force	400 to 600 N	Static pull to value

Start with loaded weight: 22 kg marks the single-person limit, 40 kg the two-person one. Fix it and the empty shell is capped, so wall and ribs trade inside that cap. Specs that open with wall thickness end up too heavy to lift.

2. Size and Compartments Must Follow the Contents

400 × 300 × 180 mm is the common mid-size envelope, with a cavity near 360 × 262 × 152 mm. The gap is not waste: ribs, radii and draft take 8 to 12 mm. Subtract two walls from the outside and the cavity comes out that much too large, so foam cut to it will not drop in.

Explosive storage case: beige body standing end-on, rib round the lid edge, two black catches, one handle, lock hole between them on dark background

Six compartments put dividers at 4 mm with cells near 82 mm and tolerance of ±1.5 mm, so the insert lands in one piece; nine compartments lose a tenth of usable volume to dividers.

Stacking adds a constraint on every explosive storage case: base and lid bearing faces must line up, or the third tier presses on a rib edge.

3. Wall Thickness Against Rated Load

A 4.0 mm nominal wall, 5.5 mm at corners and a 3.2 mm floor minimum balances mass against stiffness. At 25 kg stacked three high, the bottom case carries 75 kg on corners and handle roots, not the floor panel. Moving to 4.8 mm adds 12 percent weight for under 8 percent more crush resistance.

Load is not a function of wall alone: rib spacing, fillet radius and the handle transition shift the bearing point toward a seam. Read the residual set after 24 hours: sag at the floor centre means a thin wall, corner distortion means the ribs are behind.

4. Static and Flame Clauses for the Contract

A resistance clause without test conditions is not a clause. Write 500 V, three probes (cavity floor, mid wall, inner lid) and a 10⁶ to 10⁹ ohm band at each. Without them, one case reads two orders of magnitude apart in two labs.

Explosive storage case: champagne body set at an angle on black, lengthwise ribs across the lid, two catches and a folding handle, thickened corner edging

Flame needs three entries: oxygen index of at least 28 percent, UL94 V-0, and glow wire at 750 °C with ignition and extinction times. Sample thickness belongs in the same sentence; ratings do not transfer.

5. Latch Strength and Carry Hardware

Latch data splits into three figures: 480 N holding force per catch, six hinge pins, an 8 mm shackle hole. Each maps to a separate failure, catch pulled open, hinge torn out, shackle sheared, so one strength number hides all three.

Acceptance item	Value	Method
Catch	480 N	Static pull, 60 s
Handle	60 kg	Loaded lift, 10 min
Sealing	IP67	1 m water, 30 min
Cycling	-20 to 60 °C	Five cycles

Handles follow the action: 60 kg static on a 25 kg load proves the root transition, wheels at 40 kg over 5000 cycles prove the axle mount. Attachments fail at the joint, so load there.

Conclusion

Sizing an explosive storage case means turning carrying, stacking and testing constraints into numbers in that order: loaded weight sets the envelope, contents set the cavity, wall and ribs carry the load, test conditions settle acceptance. A sound document beats a long parameter list: every line can be measured again. The explosive storage case that works is rarely the one with the finest numbers, but the one whose numbers can all be re-tested.

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.