Correlations between engineering parameters are an effective tool in geotechnical engineering practice. The plasticity index and soil cohesion have been shown to be strongly correlated. The same for relative density and friction angle. This study was conducted using 87 soil samples categorized as: low plasticity clay (39 specimens), high plasticity clay (22 specimens), poorly graded sand (6 specimens), and silty sands (20 specimens). The samples undergo direct shear box test (ASTM D 3080) and vane shear test (ASTM D4648) with modification established in this paper. This study intends to compare the results obtained from the vane shear test after adapting it to measure the ultimate torque under different levels of normal stress with the results of direct shear box, to evaluate the validity of the modified vane shear test in obtaining shear strength parameters for c-phi soils. This study also aims at establishing a correlation of cohesion with plasticity index and relative density with angle of friction of soils, using laboratory test data. The paper displays results of the current study and compares them to mathematical relations reported by other researchers in accessible literature.