Lightweight camping stoves by their description are made from thin steel.  


The lightweight camping stove is just as effective as the heavy stoves in heating a tent. However, not as durable and you will get about half  the stove life when compared to a heavy stove.


All collapsible stoves are also considered lightweight and are listed below.  All the collapsible stoves are made of thin metal and are about half the weight of the heavier stoves.


Recommend you read the lightweight camping stove guide which explains standard features and options. This guide  also has a section on thickness of steel by gauge.