7.4 Electric or Gas Weld Deposits are applied to one flat surface of the test piece. Double-weld passes are recommended to prevent weld dilution by the base metal. The heat of welding may distort the test specimen. When this occurs, the specimen may be mechanically straightened or ground, or both. In order to develop a suitable wear scar, the surface to be abraded must be ground flat to produce a smooth, level surface at least 63.4 mm (2.50 in.) long and 19.1 mm (0.75 in.) for the test. (See 7.5.) Note that the welder technique, heat input of welds, and the flame adjustment of gas welds will have an effect on the abrasion resistance of a weld deposit.