How do side impact door beams work?

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When a crash results from a side impact, door beams can help protect passengers. Without door beams there is little keeping a passenger from the point of impact. The standard safety equipment on most family cars now includes side impact door beams to provide a safer ride.

Door beam function

Side impact door beams are a safety feature of modern cars designed to protect the driver and passengers. When a crash occurs, door beams work by absorbing the energy created during the collision.

Door beam types

Side impact door beams can be made of steel or aluminium. Steel door beams result in a heavier vehicle, making for a more stable frame for the car. However, heavier cars also use more fuel and are therefore being replaced by lightweight aluminium beams. Aluminium beams provide the same type of safety feature with less weight making the vehicle more fuel efficient and lighter.


With the increasing size and height of vehicles on the road, including four-wheel drive and vans, side impact beams have become a more popular safety feature for cars of all sizes. The beams provide extra protection during instances when smaller cars may be struck by a larger vehicle.