Ideographic: A metal 钅 nail 丁; 丁 also provides the pronunciationRadical:

meaning for dìng:

  • - to join things together by fixing them in place at one or more points
  • - to nail
  • - to pin
  • - to staple
  • - to sew on

meaning for dīng:

  • - nail
  • - to follow closely
  • - to keep at sb (to do sth)
  • - variant of 盯