To reduce costs in the manufacturing and usage of grinding wheels, we investigate several methods of adjusting the sharpness of grinding wheels that involve heat treatment and irradiation by ultraviolet (UV) light. We confirm that heat treatment in a furnace of phenol-resin grinding wheels for aluminium leads to improved grinding ability of the wheels for stainless steel and also prevents swarf loading. Next, we clarify that treating the surface of grinding wheels by UV irradiation and heat blowing has a similar effect as heat treatment in a furnace. These treatments reduce the force ratio in surface grinding. Although UV irradiation and heat-blowing affect only the surface layer, heat treatment in a furnace affects the entire wheel. Therefore, thickness of the affected layer varies as a function of the UV-irradiation time. Finally, we applied this technique to other resin-bond wheels and found that the same effect is obtained for polyester-bond grinding wheels. However, heat treatment does not improve the grinding ability of epoxy-bond wheels with high heat resistance. In this case, UV irradiation proved to be an effective method.