A product specification that is often unfamiliar to people is the IK rating of a light 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 rating indicates how well a light fixture can withstand mechanical impact of a certain number of joules (J, a unit of energy). An IK rating is also known as impact resistance. The IK rating scale ranges from 0 to 10. The higher the rating, the better the light fixture can withstand impacts. You may sometimes also come across an IK rating higher than 10. However, this value is extrapolated from 20 joules and therefore often has not been properly tested.

Most common IK ratings

Below you will find some 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 level of impact resistance, for example for an open light fixture.
• IK 04: resistance to impacts of 0.5 joules. This is a standard-plus level of impact resistance, for example for a standard light fixture with a reinforced optical system.
• IK 07: resistance to impacts of 2 joules. This is a reinforced light fixture, for example a standard light fixture equipped with a grille.
• IK 08: resistance to impacts of 5 joules. This is a vandal-resistant light fixture, for example a closed light fixture with a glass cover.
• IK 10: resistance to impacts of 20 joules. This is a vandal-proof light fixture, for example a fully enclosed light fixture.

Which IK rating do I need?

With the ratings listed above, the light fixture may dent or bend, but the lamp itself will remain intact. To properly protect the lamp inside the light fixture, it is therefore important that the IK rating matches the function of the light fixture. Do you expect a light fixture to be subjected to heavy impacts because, for example, it is installed in a location where a lot of vandalism occurs? Then it is a good idea to choose a higher IK rating. This ensures that the light source does not become damaged unnecessarily.