Places of employment

[Nancy Jaderen]

Anders has given me good information on the Bolt Factory in Hallstahammar.Now I have aquestion on my grandfather and my mother. My grandfather,Johan Albert Jansson worked in a factory in Södertälje.Does anyone know the where  
any of these factories would have been located. Also,my mother,Ruth Hildur Jansson,worked as a cook in,what sounds like,a home for bad boys.
This was on,or close, to Lake Mälaren because on her days off she would ride her bike around the lake to a dance.I would really be interested in finding out where this was.
  Thank you
 Nancy Jaderen