How did British body armour change from steel helmets to nylon helmets?

In the British armed forces, the transition from steel to nylon headgear occurred during the 1980s.1

Following the widespread adoption of steel helmets during World War I to protect soldiers against high-velocity artillery fragments, these metal designs remained standard-issue for decades. However, in the 1980s, the British military replaced these traditional steel helmets with the first in a series of helmets fabricated from nylon.231

This shift was part of a broader evolution in modern body armour, which subsequently saw the introduction of lightweight Combat Body Armour (CBA) and later the advanced Osprey Assault system, designed to provide better protection and mobility for infantry troops in modern combat environments.1