What must a shockproof case acceptance cover at minimum?

Answer: Five items: latch retention, hinge life, cold drop, random vibration and foam recovery. Drop one and impact resistance becomes an adjective.

Is a drop weight stricter than a full case drop?

Answer: They differ. A weight tests material and ribs; a full drop tests latches and overall stiffness.

How much density deviation is acceptable?

Answer: Within 5 percent of the declared figure. Beyond that the cushioning curve shifts down as a whole.

What load should the handle carry?

Answer: Twice the rated load for 30 minutes, under 2 mm of set.

Can photographs replace a test report?

Answer: No. A specimen number, measured values, conditions and a verdict are the minimum.

Shockproof Case Acceptance: Inspection Items and Pass-Fail Rules

Quick answer: A shockproof case cannot be accepted on the phrase built to take a knock. Split acceptance into type testing, which proves the design, and routine testing, which proves the batch, with every item carrying a threshold and a specimen number.

Two Inspection Sets Behind a Shockproof Case
Hardware: Latches, Hinges and Handles
Impact and Vibration Verdicts
Foam Insert Checks and Thresholds
Sampling, Retest and the Report
FAQ

1. Two Inspection Sets Behind a Shockproof Case

Type testing covers hardware strength, cold drop, random vibration, stacking and foam on three units, and may destroy them. Routine testing covers only what leaves the unit deliverable: latch feel, hinge stroke, insert fit and marking.

Item	Type test	Routine test	Threshold
Latch retention	3 units	Feel, every unit	400 N held for 60 seconds
Hinge life	3 units	5 open-close cycles	Gap growth after 3000 cycles
Cold drop	3 units	None	Dent no deeper than 2 mm
Random vibration	3 units	None	Insert shift no more than 2 mm
Stacking	3 units	None	Height change after 24 hours
Foam	Sampled per lot	Fit, every unit	Recovery no lower than 92%

A threshold has to be a number: 400 N for 60 seconds with 0.5 mm of permanent set, not the word secure.

2. Hardware: Latches, Hinges and Handles

Hardware is where a shockproof case fails first, and where a quotation gets trimmed. On the same mould a tongue cut from 3.0 mm to 2.4 mm looks identical and loses about thirty percent of its holding force.

Shockproof case: olive green closed case on a steel table, two black latches, a moulded handle, a black valve with a red ring

Load the latch to 400 N for 60 seconds, then measure movement between tongue and keeper; over 0.5 mm fails. Run the hinge to 3000 cycles at 15 per minute with pin clearance growth under 0.15 mm, where a 5 mm stainless pin survives and a 4 mm carbon pin turns oval.

Load the handle to twice its rating for 30 minutes with 2 mm of set; breakage starts at the root fillet, so a radius under R3 belongs on the drawing.

3. Impact and Vibration Verdicts

Impact uses a drop weight rather than a whole-case drop: 5 kg from 1.0 m with a 25 mm head, striking the wall centre and one corner. Pass means a dent under 2 mm, no through crack and no white stress band inside.

The cold soak is separate: four hours at minus 25 degrees Celsius, struck within 30 seconds.

Vibration runs at 0.5 g rms from 10 to 500 Hz for 30 minutes per axis; the verdict concerns movement inside.

Test	Condition	Verdict
Ambient drop	5 kg, 1.0 m, R25 head	Dent under 2 mm, no crack
Cold drop	Minus 25 degrees, four hours	Same, struck within 30 seconds
Random vibration	0.5 g rms, 30 minutes per axis	Insert shift under 2 mm
Stacking	300 kg for 24 hours	Height change under 3 mm

4. Foam Insert Checks and Thresholds

Foam is the consumable part of a shockproof case and the easiest to swap. A lower density grade looks and feels the same while flattening the cushioning curve.

Cut a 50 by 50 by 25 mm sample and weigh it; the reading may differ from the declared figure by no more than 5 percent. Compress 25 percent for 24 hours, rest 30 minutes, then require 92 percent rebound.

Check	Method	Threshold
Density	50 by 50 by 25 mm sample weighed	Within 5% of declared
Recovery	25% compression, 24 hours	At least 92%
Residual travel	Foam under the part base	At least 8 mm
Fit gap	Feeler gauge at the cavity wall	No more than 2 mm

Residual travel is the forgotten item: a part can sit flush on 3 mm of foam and bottom out on the first drop.

5. Sampling, Retest and the Report

Sample by lot: 8 units from every 200 for non-destructive items, plus 2 for destructive ones. One failure in that pair returns the lot without retest, because it points at design or process rather than at a single unit.

Non-destructive failures may be retested: double the sample to 16, and a second failure returns the lot. A report lists conditions, specimen numbers, measured values per unit, verdicts and photographs. Averages are not accepted.

Conclusion

Acceptance translates built to take a knock into numbers: 400 N of retention, 3000 hinge cycles, a drop at minus 25 degrees, 92 percent recovery. Type testing governs the design and routine testing governs consistency, and both leave records. Put the thresholds in the contract, and a shockproof case earns its name instead of borrowing it.

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.