When comparing the NH35A and 9015, it is important to note that these are two of the most popular non-Swiss automatic movements. Both movements are made in Japan, while some NH35A movements are also made in Malaysia. Both calibers are considered to be workhorse movements and are found in many affordable microbrand/crowdfunded watches.
With all of the differences between these two calibers, the most dramatic difference is the beat rate. The Seiko NH35A beats at 21,600 bph, whereas the Miyota 9015 beats at a higher 28,800 bph.
Both the Seiko NH35A and Miyota 9015 have a quick set date.
Crown Position Functions:
The Seiko NH35A and Miyota 9015 have similar time setting functionality.
0 (against the case): Manual Winding
1 (pulled out one click): Date setting
2 (pulled out two clicks): Time setting
Rotor Winding Direction:
The Seiko NH35A is equipped with Seiko’s own Magic Lever, so the rotor winds the mainspring in both directions (bi-directional). The Miyota 9015 rotor winds in clockwise direction only.
The NH35A and 9015 measure up with a slightly different diameter and height. These two movements are not meant to be swapped, and although an experienced watchmaker can possibly pull of an NH35A/9015 mod, it would depend on the application and would not be worth the amount of work needed.
This may surprise most readers, but compared to the Seiko caliber NH35A, the Miyota 9015 costs more than double. The NH35A can be found in the range of $35 – 45 USD. The 9015 can be found in the range of $100 – 135 USD.