0.5 mm is about 24 GA which is very thin. For comparison, stainless steel metal kitchen sinks are twice as thick or more. Typical 18 GA = 1 mm or thicker 16 GA = 1.3 mm I have had a few of this type of fire ring that gets occasional use 4 or 5 times per year and they work OK but have to be replaced every couple of years due to rust and burn through. I am looking for a new one now. Haven't found a thicker, folding portable one yet so will probably get another thin one like this.