The Seiko 5Y31-5100 is a watch model based on the 5Y31 movement.
Parts List
| ESAW26JM02 | crystal |
| ESAW26JM01 | crystal |
| ESAW26JM | crystal |
| 35MA8NA1 | crown |
| 0A2600N01 | case back gasket - case back gasket |
| BPA73G | band - leather band |
| BPJ73G | band - leather band |
| BPA69G | band |
| 5Y315100 | others - case back |
| 5Y31510075 | others - case |
| 5Y31510079 | others - case |
| 5Y315340XB14 | others - dial |
| 5Y315340XG24 | others - dial |
| 5Y315350XB14 | others - dial |
| 5Y319 | others - machine code |
| 82811540 | others - case ring |
| A180BS | others - push pin |
| 0351670 | others - winding stem |
| 13SC04A2 | others - second hand |
| 0Z0060B01 | others - crown and stem gasket |
| 09T32DAM | others - minute hand |
| 09T32DAH | others - hour hand |