Production of nut-provided sheet-metal parts and nut and bolt/nut assembly used therefor

PURPOSE:To prevent the electrodeposition of paint in a tapped hole and generation of the whistling sound of the unused nut when the paint is applied on the sheet-metal parts for automobile by fixing a nut with the tapped hole filled with a specified elastic closing member to this parts and then applying electrodeposition coating. CONSTITUTION:A sheet-metal part 22, a welded nut or a piercing nut 16 and an electrical insulating heat-resistant elastic member 10 (silicone rubber) fitting in the tapped hole 18 of the nut are prepared. The member 10 is inserted into the tapped hole 18 to close the tapped hole, and then the nut 16 is fixed to the part 22. The nut-provided sheet metal part is then coated by electrodeposition.