shows the typical geometry of the slitting method with a back surface strain gauge. The strain gauges bonded on the back surface of the stressed part directly opposite the slit are sensitive to all residual stress within the specimen thickness and thus generally used for through-thickness measurements. However, the strain gauges bonded on the top surface near the slit are only sensitive to near surface residual stress (usually up to 20–25% of the thickness) and therefore are appropriate for near surface measurements. In this research, back surface strain gauges were used.