Can Gear Case cavity sizes be round numbers?

Answer: Yes, on the 25 mm module: bays of 75, 100 and 125 mm, with one liner tool for all three.

Is a 4 mm wall more durable?

Answer: Durability costs carrying comfort: 18 percent more load, 22 percent more weight.

Can an IP67 Gear Case stay under water?

Answer: No. IPX7 rates 30 minutes at 1 m, and long immersion relies on a gasket that loses rebound.

How much can the handle carry?

Answer: 1.5 times the load, so 700 N for 45 kg. Past 55 kg, add wheels or a two-person point.

How do tier counts convert to load?

Answer: Count the tiers above, not all five: four tiers at 45 kg put 180 kg on the base.

Gear Case Specifications: Size, Wall Thickness and Load

Quick answer: Write Gear Case specifications in three layers: internal size decides what fits, wall thickness and weight decide who carries it, load and stacking decide how high it goes. Push one layer and the other two send the bill.

Internal Size and Divider Modules for a Gear Case
Handle and Latch Load Points
Wall Thickness Weight and Load
Sealing Ratings and Test Conditions
Stacking and Top Load Ratings
FAQ

1. Internal Size and Divider Modules for a Gear Case

A Gear Case drawing starts from the cavity. The envelope sets van and shelf fit, the cavity sets what goes in, and the gap is wall, rib and cap. Quote the cavity at plus or minus 1.5 mm and the envelope at 2 mm: a liner 2 mm wide will not press in.

Dividers run on a 25 mm module, with 75 mm as the narrowest bay a gloved hand can reach. Depth steps in 25 mm, usually 100, 150 or 200 mm.

Item	Written as	Tolerance	Purpose
Internal size	length by width by depth	1.5 mm	liner cut to this
Outer envelope	including caps and bosses	2 mm	van and shelf fit
Divider module	multiples of 25 mm	to module	75 mm minimum bay
Lid depth	separate line	1.0 mm	height of standing items

2. Handle and Latch Load Points

The handle and latches are the only places where a Gear Case trades force with the outside, so both follow loaded weight: 700 N static at 45 kg, 350 N per strap anchor.

Gear Case: a close view of the moulded handle fused to the orange wall, an open latch below it with ribs on seat and tongue

The handle root has to land on a rib, never on flat wall. At 700 N a 3.5 mm panel creeps at 40 °C and whitens within a year, so extend each end 40 mm into a vertical rib or mould a 6 mm collar.

Latches are sized from gasket reaction, not case weight. A 10 mm cord at 25 percent pushes 150 N per metre, so two latches on a 1.6 m case share 120 N each and a 350 N catch keeps 2.9 times margin. Past 1.2 m, add a third.

3. Wall Thickness Weight and Load

Thickness and load are not linear. A 3.0 mm wall gives 4.8 kg and 40 kg on the lid, 3.5 mm gives 5.9 kg and 55 kg, 4.0 mm gives 7.2 kg and 65 kg. From 3.5 to 4.0 the load rises 18 percent while weight rises 22 percent.

Wall	Empty weight	Top load	Deflection at 300 N
3.0 mm	4.8 kg	40 kg	2.8 mm
3.5 mm	5.9 kg	55 kg	1.9 mm
4.0 mm	7.2 kg	65 kg	1.4 mm
4.5 mm	8.6 kg	70 kg	1.2 mm

Every load figure needs its condition: the same Gear Case holds 55 kg on supports 400 mm apart and 38 kg at 600 mm, since deflection follows the span cubed.

Weight needs a stated basis: a 15 mm EVA liner adds 0.6 kg and wheels 1.1 kg, so 5.9 kg arrives at 7.6 kg.

4. Sealing Ratings and Test Conditions

A rating means nothing without its test conditions. Common steps are IP65 for jets and IP67 for short immersion; the difference sits in the method.

Gear Case: an orange case open upright, ribs and a handle slot in the lid, an orange jacket, black gloves and an orange helmet inside

Dust follows IP6X: talc at 2 kg/m³, 2 kPa vacuum inside, eight hours, no powder in the cavity. Water follows IPX5: a 6.3 mm nozzle at 12.5 L/min from 3 m for three minutes. IPX7 is 1 m of still water for 30 min, water and shell within 5 °C.

5. Stacking and Top Load Ratings

A tier count alone is useless; state the base load and the time. Five high at 45 kg puts 180 kg on the bottom lid, and residual set after 24 h should stay under 2 mm at 40 °C, since a room test shows six tenths of the hot figure. Top load dishing is short, stacking creep is long.

State the support surface too. On 700 mm rack beams the base spans open and contact shrinks to 60 mm a side, halving the floor capacity, so a Gear Case figure without it cannot be checked.

Conclusion

Cavity, wall and load pull against each other. Fix the cavity, then the carry points, then the wall, then check stacking; skipping a step moves the cost elsewhere. Put conditions and tolerances in one table and the Gear Case specification survives.

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.