Hallowell DuraTough all-welded storage and combination cabinets. Classic Series cabinets are fabricated from prime grade cold rolled sheet steel. Heavy Duty Cabinets are fabricated with 16 gauge sheet steel and are fully-welded creating a rigid, durable unit. Extra Heavy-Duty Cabinets are fabricated with 14 gauge sheet steel which is 25% thicker than 16 gauge providing MAXIMUM durability.