Classic legs are made from 3/8" thick steel and are perfect for the majority of projects, as long as your surface weighs less than 60kg.Heavy Duty legs are made from 12mm thick steel and are incredibly robust. They are only necessary for very heavy duty projects. They can be used to create very large and sturdy desks and dining tables.We also offer bench-height legs (16 inch) in 12mm thickness so you can have a matching set for your table, if required.