The main factor that differentiates hydraulic from non-hydraulic mortar is its strength, which in turn has an effect on how it can be applied during a job as well as what kind of tools are required to work with it. Hydraulic mortar is stronger than non-hydraulic and its strength comes from the fact that it has a high amount of lime or gypsum in comparison to portland cement which makes up for around 20% while hydraulic mortars have 60% or more of either lime or gypsum with only 40% portland cement. Non-hydraulic mortar is less strong than hydraulic mortars as it has a higher amount of portland cement which makes up for around 20% while non-hydraulic mortars have 40% or more with 60% portland cement and no lime or gypsum. In general, the strength factor affects how heavy tools are, for example when working with non-hydraulic mortar it is necessary to use a cement mixer while hydraulic mortars can be mixed by hand.