There are metals that can resist bullets. But it would be difficult to carry bulletproof vests made of metals. The more convenient option is a lighter, strong fibre which will prevent the bullets from hitting your body and easy to wear at the same time. And that is why Kevlar is used for this purpose.
Kevlar is one of the strongest materials on earth; when it is woven into fabric, it is five times stronger than steel. It can even resist knives. Kevlar has a strong ring-like structure and can resist high temperatures. It is used for making many types of body armour.
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