There is a LOT of vendors out there, with plate carriers and plates made by many firms, from many different materials. Ceramic plates are, apparently, the best….but they are a lot more expensive …but lighter. Steel is cheaper and a bit heavier for nearly the same performance.
One thing I find interesting is that MANY of the steel plates offered are made from AR400 or AR500 steel. Lots of references to those two numbers. Fully 2/3 of the steel “Ballistic Plates” offered are advertised to be made from one of those two alloys. Being the type of person who likes to learn things, I researched these two steels (as well as a bunch of the others that are offered)
But, sadly, neither of those commonly used steels are intended to be used as Armor Plate….they don’t have a great deal of penetration resistance, nor are they intended to be used as “Armor”. Instead, they are meant to be “Abrasion Resistant”….and dent resistant…Neither of these steels is supposed to be “Armor”. They aren’t much better for “armor” as we think of it than general cold rolled steel.
Why do “armor” vendors sell plates made with non-armor steel? More importantly, why do people buy enough of them that they are even for sale?