Study of Knoop microhardness anisotropy on the (001) face of potassium bichromate single crystals

► Knoop microhardness measurement on (001) face of KBC crystals was made. ► Results reveal maxima and minima of hardness for the 〈110〉 and 〈100〉 indenter orientations. ► The differences between maxima for the [110] and [11¯0] directions were observed. ► The differences between minima for the [010] and [100] directions were observed. ► Computed effective resolved shear stress explains the experimental results.