A state of being bent or twisted out of true, or out of alignment. The amount of warp that occurs during welding of sheet and plate material depends on the amount of heat that spreads away from the weld and through the parent metal. Some warping occurs when welding heat relieves strains left in the metal after rolling. Warping can be reduced by using jigs, chill bars, and plates to absorb excess heat. The backstep weld sequence also helps reduce warps. See EXPANSION and CONTRACTION; SHEET METAL WELDING, PREHEAT, and BACKSTEP SEQUENCE.