Is 6 kg per tray a limit or a recommendation?

A: A limit, set by the 30 N lug allowable and the foam pillars. Past it the 2 mm fillet at the lug root fails first.

Why 45 mm of clear height instead of 60 mm?

A: 280 mm inside covers 3×(40+45)=255 mm plus 25 mm of lid pad. Three trays at 60 mm would need 300 mm, so the factory multi-layer compartment tool storage box grows to 380 mm outside or drops to 12 kg.

Does IP54 hold up in a machining shop?

A: Enough for the shell. Grade 5 handles chips, grade 4 wash-down, and a night in the open still lets water in at the lid line.

Factory multi-layer compartment tool storage box

Q: Why does the factory multi-layer compartment tool storage box stop at 12 cells?

A: Clear width. At 12 cells it is 55 mm, one alignment for a gloved hand. At 18 cells it drops to 40 mm and the mean pick rises to 3.0.

Quick answer: Factory multi-layer compartment tool storage box: 560×400×330 mm outside, 510×350×280 mm inside, three trays at 6 kg each, twelve cells of 55×70×45 mm.

Two ledgers inside the factory multi-layer compartment tool storage box
18 kg through the factory multi-layer compartment tool storage box
Twelve cells of 55×70×45 mm
The 2.5 actions behind one pick
Stacking 5 high, a 1.0 m drop and IP54
FAQ

1. Two ledgers inside the factory multi-layer compartment tool storage box

More compartments is not automatically better. Trays decide how many slices come out of 280 mm of height, cells decide how finely each slice is cut. Every extra tray costs 40 mm of structure plus 45 mm of clear height, every extra column costs 55 mm of length. Only two figures survive: 45 mm clear height, 55 mm clear width.

The factory multi-layer compartment tool storage box measures 560×400×330 mm outside with a 3.5 mm wall, 510×350×280 mm inside, 5.2 kg empty. The stack came first: 3×(40+45)=255 mm, 25 mm for the lid pad, outside closed at 330 mm.

Table 1: how the trays divide the height

Tray level	Load per tray	Cell layout
Upper	6 kg	4 columns × 2 rows, 8 cells of 55×70×45 mm
Middle	6 kg	6 columns × 2 rows, 12 cells of 55×70×45 mm
Lower	6 kg	two full-length slots, 170×210 mm free

The 6 kg per tray is a ceiling, not an average. Past it the 2 mm fillet at a lug root fails before the tray does.

2. 18 kg through the factory multi-layer compartment tool storage box

Each tray is a 3.5 mm PP pan on four lugs moulded into the wall, 45 mm above the box floor. At 6 kg evenly spread it sags 1.5 mm at most; half a millimetre more opens a gap between cell wall and shell.

Factory multi-layer compartment tool storage box showroom shelving with black hard cases in rows, orange and sky blue shells between them, pale wood floor

Off-centre load is the common case: 6 kg in one cell puts about 15 kPa on a 3850 mm² floor, so the floor goes from 1.0 mm to 1.2 mm with a 1.5 mm upstand. Load 18 kg plus 5.2 kg of shell is 23.2 kg, a 227 N pull on the 400 N handle, a margin of 1.76.

Table 2: four ways one tray meets load

Load per tray	When it happens	Tray response
6 kg even	all cells filled evenly	sag ≤1.5 mm, no gap
6 kg in a corner	heavy parts in one cell	15 kPa, 1.2 mm floor
18 kg transient	1.0 m drop on a corner	lug in shear, 30 N point
90 kg long term	stacked 5 high, 3 months	creep ≤0.8 mm

Sequence decides lug life: the middle tray needs the top lifted out first, and both are carried by their short edges, never the middle of a long edge with one rib over 510 mm. Each lug is rated 30 N and sees 14.7 N.

3. Twelve cells of 55×70×45 mm

The 12 cells run 6 columns by 2 rows over 330×140 mm, and 170×210 mm stays uncut as a full-length zone. The arithmetic is blunt: 510 mm holds nine columns at 55 mm, which squeezes each cell to 40 mm, too narrow for a gloved hand.

Fifty-five millimetres comes from a gloved index and thumb closed at 48 mm plus 7 mm of slack; five less and the hand enters sideways.

Cell depth 45 mm and clear height 45 mm are one number, because foam pillars fence the cells and pillar height is clear height. At 60 mm pillars three trays need 300 mm, beyond the 280 mm inside, so the stack falls to two trays and the load to 12 kg.

4. The 2.5 actions behind one pick

An action is one hand movement with one purpose: lift the lid, lift out a tray, reach and align. With three trays used evenly the expected tray moves are (0+1+2)/3=1.

Factory multi-layer compartment tool storage box sample wall, pale wood shelves in long columns, small cases sorted by colour from red to black

Add one lid lift and 0.5 for the reach, since 6 of the 12 cells sit on an edge, and the mean is 2.5. Cut the same factory multi-layer compartment tool storage box into 18 cells and clear width falls to 40 mm, the mean rises to 3.0.

Table 3: what each layout costs per pick

Cell layout	Width × depth	Full-length zone	Mean actions
12 cells (6 × 2)	55×70 mm, 45 deep	170×210 mm	2.5
18 cells (9 × 2)	40×70 mm, 45 deep	140×210 mm	3.0
8 cells (4 × 2)	80×70 mm, 45 deep	180×210 mm	2.2

5. Stacking 5 high, a 1.0 m drop and IP54

Stacked 5 high, the bottom lid carries 4×18 kg=72 kg over 560×400 mm, 3.2 kPa. Modest but permanent: in three months PP creeps, the lid sags past 1 mm, latch preload fades and dust enters at the lid line. Four latches at 300 N give 1,200 N and pull spacing on the 560 mm edge to 187 mm; two latches at 280 mm would double that sag.

Drop testing runs at 1.0 m with 23.2 kg aboard: no latch opens, no tray jumps its lugs, no pillar cracks. IP54 splits into grade 5 against chips and sanding powder, grade 4 against angled wash-down, with no claim about standing water. In this factory multi-layer compartment tool storage box the −15 °C to 60 °C range belongs to the PP shell and the EPDM seal; at 60 °C the modulus falls to about 60 percent, so the 400 N handle is re-checked at 320 N.

Conclusion

Factory multi-layer compartment tool storage box dimensions are pinched between two numbers: 45 mm of clear height sets how many trays fit, 55 mm of clear width sets how many cells each tray takes. Twelve cells hold the pick at 2.5 actions and 18 cells push it to 3.0, while three trays of 6 kg reach 23.2 kg on a 400 N handle. Stacking 5 high ends at four latches and 45 mm foam pillars.