We recently had a customer ask us: How thick is the steel in your Tornado Alley Armor safe rooms? Answer: Regarding our steel, you’ll likely be comparing apples to oranges. Unlike nearly all other manufacturers, we use HOT ROLLED ASTM 1011-CS Type B 10-gauge (0.135), a tempered steel. It performs entirely different than the commonly-used A36 COLD ROLLED plate steel, which has to be much thicker since it hasn’t been heat treated. It’s performance vs A36 is analogous to using lightweight, resilient Kevlar vs 1″ thick, heavy lead plates for body armor. Similar principles apply. If you’ve watched our impact testing video you’ll see how the NINE 15 lb 2×4’s just bounce off our walls vs exploding on impact as they do with the thicker walls. Only FOUR impacts were required…we asked for the rest to make a point.
The latter makes for good video ‘wow’ effect, but it demonstrates the lack of malleability & resiliency of welded steel plate steel. A 2×4 may shatter, but something harder, like a fence post, could potentially puncture or rip cold plate steel whereas our tempered steel will simply deflect slightly while the impact energy dissipates into the structure instead of staying concentrated at the point of impact. It’s pretty remarkable, really. Additionally, the customer is ultimately paying for the cost of the steel, so a safe room with 1/4″ thick walls is going to weigh nearly twice as much as one of ours of the same size, so you’re paying for at least 1,000 lbs or more of unnecessary steel with the other guys. Watch the impact testing video here: Impact Testing at Texas Tech
How thick is the steel in your Tornado Alley Armor safe rooms?
