304L-alloy is great for wood burning applications by doing a great job preventing corrosion in wood burning environments. Not to be confused with basic 304, 304L is a low-carbon stainless steel. 304L is significantly different from basic 304, as it is much more resilient to corrosives and rust. Making this an excellent choice for solid fuels such as wood or wood pellets.

316L-alloy has more molybdeenum and nickel and slightly less chromium than 304-alloy. The result of these slight differences is that 316 stainless steel is substantially more resistant to corrosion.  Taking this one level further, 316L is processed as a low-carbon alloy making it more resistant to corrosion than basic 316. 316L is an excellent alloy for coal, oil, and noncondensing or lower efficiency gas appliances.

316 Ti-alloy adds both molybdenum and titanium to 304-alloy, giving excellent corrosion resistance in acidic environments and high heat corrosion resistance. This corrosion resistant stainless steel alloy takes it up another notch making it a great choice for wood, coal, oil, and noncondensing gas.

AL 29-4C alloy, the most corrosion resistant of all alloys, It is a superferritic stainless steel designed by Allegheny Ludlum  in the  early 1980s.  It is good for all gas appliances, especially higher efficiency high-condensing appliances.  With it's superferritic properties it the best choice for combating the high acidic bi-product of burning corn. With the lower temperatures of burning corn and high-efficiency gas furnaces this is the best choice, however it is not as good as 316 Ti in high temperature environments.