There are a number of studies on chemically strengthened glass. Most of them are strengthened in molten salt bath below transformation range of glass. This research is distinguished from the aforementioned studies in that single $KNO_3$ powder was used by employing screen printing technique. In this study soda-lime-silicate(SLS) glasses for bulletproof glass application with various thicknesses were used. The maximum value of the bending strength is 791MPa heat treated at $480^{circ}C$, which is about 4.3 times higher than the parent glass, which is the highest strength of all soda-lime glasses. In this study, it is also observed that Vickers hardness increased to $657H_v$, which is about 15% higher than the parent glass($568.7H_v$) and fracture toughness was not changed. Depth profiles measured by electron probe micro analyzer(EPMA) showed a correlation between the migrations of $K^+$ ions with bending strength of ion exchanged glasses.