AISI 304 is the type of stainless steel with food-grade certification that complies with all the resistance and corrosion requirements provided for by the reference standards.  It is so stable as to guarantee almost eternal life and top hygienic conditions without the stored product being contaminated in any way by any chemical modifications in the material. For all its units Coldline uses only AISI 304 stainless steel.

The market offers other types of steel that are often generically described as stainless steel without specifying their nature to hide their poor quality. AISI 202 for instance costs positively less than 304 and duplicates nearly perfectly its aesthetic characteristics. The ageing process of AISI 202 is very fast because of its lower resistance to corrosion. In a short period it undergoes a decay that starts with a change of colour (yellowing) caused by the aggression of the acid agents normally released by products such as dairy, meat, fish, etc.

Many rely on the “magnet test” to identify the quality of the steel: attack = poor quality, no attack = good steel, however the magnetism of steel is not a quality classification system, it just identifies the steel belonging to different macrofamilies: austenic (the magnet does not stick) or ferritic (the magnet sticks). For instance both AISI 304 and AISI 202 belong to the austenic family so they can often be mistaken.

It is right to evaluate carefully the quality of the products you intend to buy, asking, if necessary, also the certificates for the materials used, to be certain they meet the desired quality requirements fully.