The factors such as weight, stray load losses and minimum cost are kept in mind while selecting the material for transformer tank. The material must be capable to withstand stresses due to jacking and lifting and must have capacity to house cores, windings and internal connections giving adequate clearance between the windings and the walls. Rolled steel plates are used for tank bodies of most of the transformers. Small tanks are generally welded from steel plates. The larger tanks are assembled from boiler plates. Usage of aluminium for transformer tank reduces the weight and the stray magnetic losses. However, it increases the cost and also needs special attention for lifting to present stressing. The aluminium tanks are usually made of cast aluminium tank parts, which are mounted on a shallow mild steel tray and are arranged to carry the main lifting.