Ford KA Boron and Ultra High Strength Steel

To achieve the best combination of light weight and structural performance, high-strength and Boron steels were employed in the critical load-bearing parts of the structure, such as in the main pillars and crash zones. High-strength and Boron steels can be used in thinner gauges than conventional steels, reducing weight while providing improved strength and rigidity.

In frontal impacts, the all-new Ka channels energy through the two side rails, with a third load path through the suspension subframe. For side impacts, the B-pillars, rocker panels and doors feature carefully designed reinforcements to ensure the body sides retain their structural integrity and minimise intrusion into the passenger compartment.
 
Source: Ford Ka Press Pack