The hot water storage tank made of stainless steel plates are constituted by forming the stainless steel plate of excellent press workability, welding property and stress corrosion cracking resistance into hemispherical shape by working means of drawing and bulging by press molding, spinning, or the like, and joining two of hemisphericalshells formed in hemispherical shape by a joining means to assemble the whole into spherical shape. プレス加工性、溶接性、耐応力腐食割れ性に優れたステンレス鋼板を、プレス成形による絞り加工や張り出し加工、またはスピニング加工などの手段によって半球形に成形し、その半球形に成形した半球殻2個を溶接などの接合手段で接合することにより全体を球形に組み立てて、ステンレス鋼板製貯湯タンクを構成する。 - 特許庁