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cialized decorative effects. Automated machines are generally used for finishing. Peening Peening to increase fatigue resistance or to increase stress corrosion resistance is essentially a uniform "hammering" operation. Uniformity of bead size and con- trol of the number of nonround and angular particles included is critical to process performance. The key consideration is impact intensity, which must be specified as minimum and maximum. Nozzle angles should be as close to a right angle as possible without excess bead consumption. In general, the larger bead sizes, because of their resistance to breakdown, will prove most cost effec- tive. In peening fillet areas, it is a standard rule that beads no larger than one half the radius should be used. Deburring The key considerations in deburring are usually a combination of programming sur- face finish, while achieving sufficient impact intensity to remove or depress the burr. Bead size, which governs finish, must be adjusted to an adequate peening intensi- ty with velocity. Proper nozzle angle will optimize consumption. 56