chain saw guide bar comprising three plates joined by welding , having a nose , a clamping area and a guiding groove for the chain , where the bending stiffness in a zone immediately in front of the clamping area is increased by omitting welds in the zone to make sure that the compressed plate buckles outward when overloaded . the zone extends in the longitudinal direction of the bar for a distance greater than the groove depth and less than the bar width .