What Does the IK Rating of a Fixture Mean?

A product specification that is often somewhat unfamiliar to people is the IK rating of a fixture. In this blog, we explain what IK ratings are, provide examples of common IK ratings, and explain when this specification is most relevant.

What Are IK Ratings?

This value indicates how well a fixture can withstand mechanical impact from a certain amount of Joules (J, the unit of energy). The IK rating is also known as the impact resistance. The scale of IK ratings ranges from 0 to 10. The higher the value, the better the fixture can withstand shocks. Occasionally, you may encounter an IK rating higher than 10. However, this value is extrapolated from 20 Joules and is often not well tested.

Most Common IK Ratings

Below are examples of the most common IK ratings, with their corresponding mechanical impact resistance:

• IK 02: Resistance to impacts of 0.2 Joules. This is a standard impact resistance for, for example, an open fixture.
• IK 04: Resistance to impacts of 0.5 Joules. This is a standard plus impact resistance for, for example, a standard fixture with a reinforced optical system.
• IK 07: Resistance to impacts of 2 Joules. This is a reinforced fixture, for example, a standard fixture equipped with a grid.
• IK 08: Resistance to impacts of 5 Joules. This is a vandal-resistant fixture, for example, a closed fixture with a glass cover.
• IK 10: Resistance to impacts of 20 Joules. This is a vandal-proof fixture, for example, a fully closed fixture.

Which IK Rating Do I Need?

With the values listed above, the fixture may experience dents or bending, but the lamp itself will remain intact. To adequately protect the lamp in the fixture, it’s important that the IK rating matches the function of the fixture. Do you expect the fixture to endure significant impacts, such as if it is installed in an area prone to vandalism? In that case, it’s a good idea to look for a higher IK rating. This way, you can ensure that the light source is not unnecessarily damaged.