HEATMOR® has been producing grade 409 stainless steel outdoor furnaces for over 20 years. All furnace components that come in contact with fire or water are manufactured using grade 409 stainless steel. Residential models are manufactured with 10 gauge and commercial models with 7 gauge (600 CSS & 800 CSS).
Prior to 1993, HEATMOR® manufactured outdoor furnaces using carbon steel. HEATMOR® chose to begin using grade 409 stainless steel due to its improved oxidation and corrosion resistance versus carbon steel. It was found that outdoor furnaces manufactured using grade 409 stainless steel would last approximately three times longer than furnaces manufactured using carbon steel.