The Seiko 1F20-F040 is a watch model based on the 1F20 movement.
Parts List
| 180W26JK | crystal |
| 180W26JK01 | crystal |
| 6K35AFTJW0 | crown - crown |
| 6K35AFTJ Ers. 35MR8NF1 | crown |
| FH2130B01 | case back gasket - case back gasket |
| EA0040B0 | case back gasket |
| 86581700 | crystal gasket |
| 86581701 | crystal gasket |
| 4156JB | band - band |
| 4156JB-LKG | band - link |
| 4156JB-BK2G | clasp - buckle |
| 4156JB-PB1 | clasp - parts for buckle |
| 1F20F070XN14 | others - dial |
| 1F20F080XS19 | others - dial |
| 1F20F090XN14 | others - dial |
| 81181459 | others - bracelet fixing pipe |
| 82820780 | others - case ring |
| 81606899 | others - bracelet fixing pin |
| 1F20F040WFA | others - case |
| 1F20F040 | others - case back |
| 0351807 | others - winding stem |
| EA0040B0A | others - crown and stem gasket |
| 07Y48NGM | others - minute hand |
| 07Y48AAM | others - minute hand |
| 07Y48NGH | others - hour hand |
| 07Y48AAH | others - hour hand |
Caliber 1F20
