BS - Breaking Strain is the load at which the item can expect to break. A safe working load can be 25 to 50% of this load depending on the usage and the standard required. TDL - Tested Deformation Load is the load at which the item begins to deform (bend). This is a much safer and more accurate system for stainless steel, as the actual breaking strain can be up to 4 times higher. MWL - Maximum Working Load is the load recommended and is usually less than the TDL.