Abstract: A surface formed by grate bars in pasteurizers and the like. The grate bars are movable so as to perform a pilgrim step-like or reciprocating movement. The grate bars are placed on sectional girders. The ends of the grate bars placed on the sectional girders are Z-shaped. Each sectional girder has at its upper end face a groove-shaped recess and an elongated slot-like recess vertically spaced from the groove-shaped recess. The end of each grate bar has an opening for inserting the grate bar into the slot-like recess of the sectional girder. By inserting an end of a grate bar into the slot-like recess and raising the end of another opposite grate bar, the two facing grate bar ends are vertically and laterally centered.