How thick does steel need to be to stop bullets?

What will AR400 steel stop?

1/4” AR400 Designed to handle centerfire handguns up to 45ACP. The 1/4” AR400 works with 38sp, 9mm, 40S&W and similar calibers. 3/8” AR550 Designed to handle magnum handguns and rifles up to 308, also great for 223/5.56, 5.45x39, 7.62x39 and similar.

Is AR400 stronger than AR500?

The major difference is impact resistance. AR500 has higher abrasion resistance, but AR400 has higher impact resistance. Since AR400 plate is softer than AR500 plate, it can withstand more impact without cracking or shattering.

What is AR400 steel used for?

AR400 stands for abrasion resistant with a minimum hardness on the Brinell scale of 360 and a nominal hardness of 400. Typical uses of AR steel, which is classified as a carbon steel, include chutes for gravel or coal in mining, liners for heavy equipment, and rifle range silhouette targets.Feb 8, 2011