The lecture emphasize the importance of washers in reducing stress concentration. If a washer is omitted in an assembly involving a bolt and nut, where is the stress concentration most likely to occur? At the interface between the bolt head and the workpiece Within the threads of the bolt In the center of the workpiece being clamped At the edges of the hole in the workpiece

The stress concentration is most likely to occur at the edges of the hole in the workpiece. Washers are used to distribute the load of the bolt and nut over a larger area, reducing the stress concentration at the edges of the hole in the workpiece. Without a washer, the load is concentrated at the edges of the hole, which can lead to increased stress and potential failure of the workpiece.