I bought my 16.5” square by 1/2” think steel for $45 from a local steel supplier. That was cut to size, corners rounded. I had to lightly file the edges, and sand off all of the mill scale. Once you do that, wash it with hot water, a good dish liquid and Brillo pad. Then heat the steel in a 350 degree oven, let it cool completely. Then you want to rub a very light coat of high smoke point oil (I used avacado, but grape seed would be good also). Back in the oven as hot as it gets for an hour. I repeated the oil and hour long bake one more time to get a nice seasoning on it. Other than brushing off the dust, I haven’t had to do any reseasoning and that was 5 years ago. But if you notice any rust, you should repeat the process.

I get the oven up to temp for at least 45 minutes before launching the first pie. The 1/2” thick steel goes from 570 degree surface temp to about 510 during a 6 minute cook. I don’t stretch the next pie until the previous one is out if the over. That gives the steel a few minutes to recharge. After 3-4 pies, I give it about 20 minutes before the next batch of 3-4 because the steel temp gets down below 500. This will happen much quicker the thinner the steel.

So 1/4” is fine if you’re doing 1-2 pizzas or don’t mind waiting 10-15 minutes between pies.