What is the highest IK rating?

IK10 is the highest rating in the base IEC 62262 scale, at 20 joules - equivalent to a 5 kg mass dropped from 40 cm with a steel striking element. Some suppliers quote levels beyond the base table, such as 50 joules; if you see one, ask which test method and which edition of the standard it was assessed against.

What is the difference between IK and IP?

IK (IEC 62262) rates protection against mechanical impact from outside. IP (IEC 60529) rates protection against ingress of dust and water. They are independent: an enclosure can be IP65 and IK07, or IP20 and IK10. The standards are also linked in one way - after the impact test, the enclosure must still provide its rated IP protection.

Does an IK10 case protect what is inside?

No, not by itself. IK tests whether the enclosure survives and continues to seal. It says nothing about the shock transmitted to the contents - that is the job of the foam interior. A shell can pass IK10 and still deliver a lethal shock pulse to a fragile instrument unless the interior is designed for it.

Does the IK rating still apply at low temperature?

The rating is determined under defined laboratory conditions, and polymers become stiffer and more brittle as temperature falls. A shell that passes at room temperature can behave differently in a cold environment. If the case will be used in the cold, ask for impact behaviour at your service temperature rather than extrapolating from a room-temperature certificate.

How do I verify an IK test report?

Check that it names the standard and its edition, the striking element and energy, the number and location of impacts, the sample conditioning, whether the rated IP protection was retained after impact, and whether the sample was a production moulding from the actual tool rather than a laboratory prototype.

IK Impact Rating Explained for Protective Cases

IK codes appear on more and more protective case specifications, usually as a single number with no context: IK08, IK10. The number is meaningful, but only if you know what it was measured on, at what temperature, and what it does not cover.

What IK measures

The IK code is defined by IEC 62262 (published as EN 62262 in Europe). It classifies the degree of protection an enclosure provides against external mechanical impact, expressed as impact energy in joules. The test delivers a defined energy through a defined striking element at defined points, and the enclosure must survive it.

IK code	Impact energy	Equivalent impact	Typical situation
IK07	2 J	0.5 kg from 400 mm	A hand tool slipping and striking the case; a cable drum bumping into it
IK08	5 J	1.7 kg from 300 mm	Trolleys and moving equipment hitting the case; moderate impacts in transit
IK09	10 J	5 kg from 200 mm	Heavy tool impacts; rough handling in industrial and public environments
IK10	20 J	5 kg from 400 mm	Deliberate abuse, heavy tool blows, impacts from moving vehicles

Outdoor-grade hard case built for impact-prone duty — IK rates the shell, not the contents — write this into the specification.

Lower codes - IK01 to IK06 - cover progressively lighter impacts below one joule up to one joule. The scale is not linear: IK07 to IK08 is two and a half times the energy, and IK08 to IK10 is four times. Each step up is a substantially more robust shell, not a marginal one.

IK is not IP

The two codes address completely different threats and are frequently confused because they sit next to each other on a datasheet.

	IK	IP
Standard	IEC 62262	IEC 60529
Protects against	Mechanical impact from outside	Ingress of solids and liquids
Expressed as	Two digits after IK, mapped to joules	Two digits: solids, then liquids
Independent?	Yes - a case can be IP67 and IK07, or IP20 and IK10	Same - neither implies the other
Where they meet	After the impact test, the enclosure must still deliver its rated IP protection	Same test sequence

That last row matters. A cracked or deformed shell loses its seal, so impact damage and ingress protection are coupled. It is also why a case that has taken a heavy knock should be re-checked for sealing, not just looked at.

The rating applies to the shell, not the contents

This is the single most important thing to understand. IK tells you whether the enclosure survives and continues to seal. It does not tell you what shock reached the equipment inside - that depends entirely on the foam interior, the support geometry and the clearance. A shell can pass IK10 and still transmit a shock pulse that destroys a calibrated instrument.

Shell rating and content protection are two separate specifications. Ask for both.
The foam is a shock absorber, not a filler. Its density, thickness and support points set the transmitted pulse.
Isolation matters more than hardness. A very stiff shell with no isolation transfers more, not less.
Verify at system level. The meaningful test is a drop test with the actual payload instrumented or inspected, not the shell rating alone.

Three limits of the rating

The number is measured under defined conditions, and your conditions are probably different. Three gaps come up repeatedly in practice.

Temperature. Polymers stiffen and become more brittle as temperature falls. A shell rated at laboratory conditions can behave very differently in a cold winter environment. If cold service matters, ask for impact behaviour at your service temperature.
Repetition. The classification is a defined energy at defined points. It is not a statement about surviving that impact hundreds of times in the same place over a service life.
Where the impact lands. Impacts are applied at prescribed points and avoid edges and hardware. Real impacts do not - a corner or a latch is a very different event from the centre of a flat face.

Material behaviour

Different shell polymers reach the same rating by different routes, and they degrade differently. A material that absorbs impact by flexing needs room to flex and can be sensitive to temperature and to notches; a material that absorbs it by distributing load through a thicker section tends to be heavier. Neither is universally better - the right choice depends on whether the case will be dropped in the cold, dragged over gravel, or stacked under load.

How to verify a report

An IK claim is only as good as the document behind it. When a supplier quotes a rating, ask for the report and check these points.

Which standard and which edition - IEC 62262 or EN 62262, with the year.
The striking element: mass, material, radius, and the energy delivered.
The number of impacts and the points at which they were applied.
How the sample was conditioned before testing, especially temperature.
Confirmation that the rated IP protection was retained after impact.
Whether the sample was a production moulding from the actual production tool.

Specifying IK without over-specifying

A higher code costs more and usually weighs more. Match the rating to the actual impact risk rather than defaulting to the maximum: light handling and indoor storage rarely justify the top of the scale, while public spaces, industrial floors, vehicle transport and abusive handling often do.

Use environment	Risk profile	Reasonable starting point
Office, studio, controlled storage	Accidental knocks, light tools	Lower half of the scale
Workshop, service van, field survey	Tool drops, equipment striking the case	IK07 to IK08
Industrial floor, warehouse, logistics	Trolleys, moving equipment, stacking	IK08 to IK09
Public space, military, heavy site use	Deliberate abuse, heavy impacts	IK09 to IK10

A rating is an input to a decision, not the decision itself. Combine it with a drop test on the real payload, an ingress check, and a look at how the interior is supported - then you have a specification worth writing into a purchase order.

IK Impact Rating for Protective Cases: What IK07 to IK10 Actually Mean