Why hold one +1.0 mm bore instead of tuning clearance per size?

A: Because clearance answers to a fingertip, not a diameter; tiered offsets would triple the gauges for no gain.

Do 24 positions cover a working set?

A: Eighteen of the 24 sit between 10 and 22 mm; the slot takes the rest above 24 mm.

Why stop floor sag at 1.5 mm rather than 2 mm?

A: Only 57 mm separates plate from lid recess, and at 2 mm the plate meets the lid.

Is IP54 enough at a repair bench?

A: It stops dust and nothing beyond splash.

Auto repair socket wrench tool box casing

Quick answer: Auto repair socket wrench tool box casing at 460×340×120 mm outside, 420×300×95 mm inside, 24 bores at +1.0 mm and 30 mm deep.

Three dimension chains inside the auto repair socket wrench tool box casing
Why the holes run +1.0 mm over socket diameter
30 mm of hole depth against 1.5 mm of floor sag
From hole wall to handle: 9.3 kg of load path
A 1.0 m drop, IP54 and the −15 °C to 60 °C window
FAQ

1. Three dimension chains inside the auto repair socket wrench tool box casing

The lower half of an auto repair socket wrench tool box casing is a drilled plate, and every bore must match one fixed outside diameter. Design runs inside out: bore and pitch, then the 420×300×95 mm cavity, then the 460×340×120 mm shell.

Each chain answers one question: bore for entry, depth for stance, wall for floor stiffness. Widen the bore 0.5 mm and the socket sways; add 10 mm of depth and the 120 mm height breaks.

Table 1: socket sizes against hole sizes

Socket spec	Hole size	Tolerance
17.5 mm OD, 38 mm tall	φ18.5 mm × 30 mm	+1.0 mm bore, ±0.5 mm depth
23.5 mm OD, 38 mm tall	φ24.5 mm × 30 mm	+1.0 mm bore, ±0.5 mm depth
29.5 mm OD, 77 mm tall	φ30.5 mm × 30 mm	+1.0 mm bore, ±0.5 mm depth
24 mm and above	120 × 300 mm slot	+2.0 mm width

One offset across three sizes keeps rework simple: a drifting bore lands on the same tool correction.

2. Why the holes run +1.0 mm over socket diameter

The millimetre on this auto repair socket wrench tool box casing is sized for one hand. A thumb and forefinger need 0.5 mm per side to press at the rim; give 1.5 mm and the socket tilts.

Auto repair socket wrench tool box casing stacked four high on a steel shelf beside an open case

Twenty-four bores split 10+8+6 across 300 of the 420 mm width, leaving a 120 mm strip. Columns sit 40 mm apart, rows 34 mm, so the thinnest wall is (40−18.5)/2, about 10.7 mm. A seventh column drops the pitch to 32 mm and ovalises the bore.

Table 2: how the bores sit on the plate

Hole size	Location on plate	Count
φ18.5 mm × 30 mm	front, 2 columns × 5 rows	10
φ24.5 mm × 30 mm	middle, 4 columns × 2 rows	8
φ30.5 mm × 30 mm	rear, 3 columns × 2 rows	6
120 × 300 mm slot	right strip, through plate	1

The split follows outside diameters: φ18.5 mm takes ten seats, φ30.5 mm six.

3. 30 mm of hole depth against 1.5 mm of floor sag

Thirty millimetres matches a 38 mm socket: 8 mm stands proud and the centre of gravity sits 11 mm below the rim, so vacuum cannot drag mass seated inside the bore.

Floor sag is separate. At 6.5 kg over 420×300 mm the pressure is 0.5 kPa, trivial until it reaches 24 hole walls at 2.7 N each, times 3 for the lid lift. A 3.0 mm floor with three 8 mm ribs sags 1.2 mm evenly, 1.5 mm at a point.

Long sockets take another route. A 77 mm socket cannot enter a 30 mm bore, so it lies in the 120 × 300 mm slot flush with the base, which sets the 95 mm cavity: 77 mm plus 10 mm of finger room plus 8 mm spare. Short sockets leave 57 mm of air the 19 mm lid recess never touches, so retention in this auto repair socket wrench tool box casing comes from the bore alone. Height reads 3.0 mm floor, 95 mm clear, 19 mm recess, 3.0 mm top.

4. From hole wall to handle: 9.3 kg of load path

Empty at 2.8 kg and loaded at 6.5 kg, the auto repair socket wrench tool box casing weighs 9.3 kg and puts 91 N on the handle at rest. Rated 300 N, the handle holds a margin of 3.3 for a kerb step.

Auto repair socket wrench tool box casing in red carried past a bench with a second red case open behind

Two latches at 260 N give 520 N across the 460 mm edge, 230 mm between catch points; move them inward and the ends lift, outward and mid-span sags past 0.6 mm.

The 5,000-cycle rating belongs to the hinge. A φ4 mm pin carries 45 N per side, and clearance grows from 0.1 mm to 0.3 mm until the lid rocks at full open.

Table 3: four tolerances and what drifts when they fail

Tolerance	How it is checked	Consequence of drift
Bore +1.0 mm, ±0.15 mm	plug gauge, every bore	under 0.7 mm jams, over 1.3 mm rocks
Depth 30 mm, ±0.5 mm	depth rule, three points	2 mm shallow leaves 10 mm proud
Floor sag ≤1.5 mm	6.5 kg load, dial gauge	past 2.0 mm plate meets lid
Latch hold 260 N	pull tester, one latch	under 200 N the seam opens

On this auto repair socket wrench tool box casing three of the four live in the plate, so inspection runs plate, lid, drop.

5. A 1.0 m drop, IP54 and the −15 °C to 60 °C window

The auto repair socket wrench tool box casing is dropped at 1.0 m with 9.3 kg aboard, once per face: no latch opens, no socket rises past 5 mm, no rib cracks.

IP54 splits cleanly. Grade 5 covers grinding dust and chips under 0.5 mm, grade 4 an angled wash-down jet; the 10 mm void is a chip trap, not a drain.

The band belongs to the PP shell and the EPDM gasket. At −15 °C impact strength falls to 60 percent, so drops are re-run at −10 °C; at 60 °C the modulus falls to 60 percent and the 300 N handle is re-checked at 240 N. Compression set must stay within 25 percent after 72 h at 60 °C.

Conclusion

Every dimension in the auto repair socket wrench tool box casing follows the plate: fix 24 positions, a +1.0 mm bore and 30 mm of depth, and the cavity and shell drop out. Loaded to 9.3 kg, the case rides inside a 300 N handle and two 260 N latches, while the 1.5 mm sag limit guards the row through every lid lift. Tolerances written on the bores, not the lid, carry 5,000 cycles and six faces of a 1.0 m drop.