Is a waterproof hard case rated IP68 better than IP67?

A: Not necessarily. IP68 depth and duration are maker-set, so an unparameterised IP68 may protect less than IP67.

Can a prototype report stand for production?

A: No. Prototypes are hand-trimmed and often single-cavity; retest production parts.

A: Depends on how water arrives: washdown favours IP66, a brief dunk IP67.

A: Standards are silent; the trade allows two years. Any mould, material or gasket change needs a retest.

Can our own immersion test replace a report?

A: It screens, not certifies. Acceptance needs third-party data. ---

Waterproof Hard Case Standards: IP Ratings and Test Conditions

Quick answer: A waterproof hard case is graded by the IP code in IEC 60529, where the second digit covers water from dripping to immersion. The number says nothing about depth or duration; only the test parameters in a report do. Specify grade, depth, time and sample state.

How to read the IP rating on a waterproof hard case
One IP number, very different test conditions
Six fields to check in a third-party report
Four things an IP number does not cover
Writing the purchase spec and acceptance
FAQ

1. How to read the IP rating on a waterproof hard case

The two digits separate solids from water: the first runs 0 to 6, where 6 means dust tight, the second 0 to 8, with 9K for high-pressure hot jets.

Waterproof hard cases usually carry IP66, IP67 or IP68: jetting, short immersion, continuous immersion. Higher is not broader, since IP66 resists jets better than IP67 tests for them. The rating also covers the enclosure only, promising nothing about pressure cycling or salt spray.

Second digit	Test	Duration
5	6.3 L/min jets	3 minutes
6	12.5 L/min at 100 kPa	3 minutes
7	Short immersion	30 minutes
8	Continuous immersion	As stated

Waterproof hard case: open, black pick-and-pluck foam in bays holding a camera body, two lenses, two boxed accessories, plain foam in the lid

2. One IP number, very different test conditions

IPX7 has a fixed baseline: sample top 150 mm below the surface, lowest point about 1000 mm, for 30 minutes.

IPX8 inverts it: depth and duration come from the manufacturer. One supplier writes 1 m for 30 minutes, another 3 m for an hour. Without those numbers an IPX8 cannot be compared.

IPX6 carries detail too: 12.5 litres per minute at 100 kPa for 3 minutes, nozzle 3 m away. Discount flow or pressure and the result flatters the product. Read the verdict too: significant ingress is a tester's judgement.

Grade	Condition	Duration	Verdict
IPX5	6.3 L/min, 6.3 mm nozzle	3 minutes	No ingress
IPX6	12.5 L/min at 100 kPa	3 minutes	No ingress
IPX7	Immersion, top at 150 mm	30 minutes	No ingress
IPX8	Depth set by maker	Stated	No ingress at stated depth

Waterproof hard case: tilted forty-five degrees under one light, handle and two latches on a diagonal, the parting line crossing the frame

3. Six fields to check in a third-party report

Standard and edition, since IEC 60529 runs to dated revisions. Sample and count, because a hand-trimmed prototype does not represent a production cavity. Pre-conditioning: water tested after thermal cycling is a different claim. Test parameters, without which a report is one sentence. Verdict with raw data, not the word pass. Issue date after the frozen mould.

Miss one and it is background.

Waterproof hard case: open on a boat deck, black gasket round the lid rim, foam bays with a wrench, pliers, cable and a grey module

Field	What to check	Common gap
Standard	Edition matches design	Only IEC 60529 cited
Sample	Production part, cavity, count	Marked prototype
Pre-conditioning	Thermal, drop sequence	None performed
Parameters	Depth, time, flow	Grade only
Verdict	Weighing or paper data	Pass, no data
Issue	Date, accreditation	Older than tooling

4. Four things an IP number does not cover

Pressure cycling: air freight and temperature swings build several kilopascals across the shell, no IP test covers it, yet it decides whether the case opens. Immersion then drop: soak 30 minutes, drop a corner, and the flange may already be offset. Salt spray and UV ageing harden the gasket while the grade stays put. Opening cycles: retest after 500. All four belong in the purchase document.

5. Writing the purchase spec and acceptance

Split the claim into five fields: grade, depth and duration, reference standard, sample state, report requirement. For example IPX7, 1 m for 30 minutes, IEC 60529, three production parts.

Fix sampling: three units per batch for immersion, one for vacuum. Reject any quote saying IP68 without depth and duration.

Waterproof hard case: on a wet teak deck, droplets on the lid, a stainless pin through the latch, a red ring around the body valve

Conclusion

The IP grade is only the entrance. What decides whether a waterproof hard case ships is the depth, duration, sample state and verdict behind it. Put those four in the purchase document, because a waterproof hard case grade is never a number on its own.

This article covers container-side specifications and design implications only, not the handling, loading or use of the contents.