From Ljusfallshammar (northwest) to Finspång (east), route 51 passes the border between Närke and Östergötland. This is forestland with many small lakes, the southeastern parts of Tylöskog.

Finspång is the centre of an old mining district. Today, the city is dominated by the ABB STAL industry, making turbines for an international market.

To the west, county route 211 leaves route 51 for Tjällmo and Borensberg, where it meets route 36. This is the road to Motala and Linköping.

Updated 1 May 1994 by Lars Aronsson.