| Manufacturer | Seiko |
| Caliber Number | 4R57, 4R57A |
| Movement Type | Automatic |
| Lignes | 12”’ |
| Thickness | 6.63mm |
| Jewels | 29 |
| Vibrations Per Hour | 21,600 bph (3 Hz) |
| Lift Angle | 53 degrees (needs confirmed) |
| Power Reserve | ~41 hours |
| Hand Windable? | Yes |
| Hand-Winding Direction | Clockwise |
| Rotor Winding Direction | Bi-Directional (Magic Lever) |
| Hacking? | Yes |
| Anti-Shock System | Seiko Diashock |
| Regulator System | ETACHRON |
| Hand Count | 5 hands |
| Functions | Hours, minutes, central seconds, date calendar subdial at 6:00, power reserve indicator spanning from 11:00 to 4:00. |
| Country of Manufacture | Japan |
| Known Models | Seiko Presage: SSA303, SSA305, SSA308, SSA343, SSA346, SSA354, SSA387, SSA392, SSA393, SSA397, SARY079, SARY081, SARY082, SARY129, SARY131, SARY135, SARY136, SARY143, SARY145; Presage Cocktail Time (Add yours in the comments below…) |
The Seiko caliber 4R57 is an automatic used by Seiko Watch Corp. in their own branded watches. Notable features of this caliber include the power reserve indicator and date subdial. This caliber has been available in Seiko models since at least 2016.
Caliber 4R57 VS SII NE57:
The caliber 4R57 is basically a Seiko-only version of the NE57. Seiko Instruments (aka SII) sells the NE57 to other manufacturers for use in non-Seiko watches.
Interesting note: Although the 4R57 features a power reserve indicator spanning from about 10:00 to 4:00, the SII drawings for the NE57 show the power reserve located from about 8:30 to 1:30.
Differences Between 4R57 and 4R57A?
The A indicates that it is the first generation of this caliber. 4R57 and 4R57A are the same. Subsequent letters indicate updates to the base caliber.
Accuracy Rating:
Seiko claims that the accuracy of caliber 4R57 is between -20 / +40 seconds per day. This rating is based on normal daily wear on the wrist in temperatures between 2 ºC and 23 ºC. When testing your watch for timekeeping, make sure it is fully wound.
Crown Position Functions:
0 (against the case): Clockwise = Manual Winding / Counterclockwise = Nothing
1 (pulled out one click): Clockwise = Nothing / Counterclockwise = Date setting
2 (pulled out two clicks): Time setting clockwise and counterclockwise
Stem Removal:
To remove the stem, make sure the crown is in position 0 or normal position (not date or time setting position). There is a lever with a small indentation for your tool. Gently press down while pulling the stem out. See official instructions below for more guidance:
Video:
https://www.youtube.com/watch?v=Ta-Qja7hJpM
