Thanks for asking for this PM, seems there's a bit of heated debate going which I'm not to excited about.
To answer your question, the grates are laser cut by a local shop I deal with in Pittsburgh. I don't own or work for this shop, which of course also means I don't own a water jet. Low carbon steel will season like cast iron, so the more you use it the better it'll cook. Feel free to contact me and I'll tell you more about it. 1-877-714-7455. Thanks again.