Helmet Mk2......but not British?

[Flying10uk]

So what's the magnet test. I don't do a ton with helmets and have never heard of it.

The special alloy steel used in the "ballistic steel helmet" (combat helmet) will have elements such as chrome, for example, which can be added to steel to make it hard and hard wearing but is non magnetic.

A bog standard mild steel is much cheaper and easier to manufacture than a special alloy steel. Therefore the "non front line/magnet" helmets were much cheaper to produce because they were made from a "standard" everyday steel.