Who Actually Makes Automatic Watch Movements

There are thousands of watch brands and there are not thousands of movement makers. Building an automatic caliber is a serious industrial undertaking, so almost every watch under about $2,000 contains a movement from one of a handful of companies — including a great many watches whose brands imply otherwise.

That is useful information rather than a scandal. Once you know which caliber is inside a watch, you know its specification, its likely accuracy, and whether anyone can repair it. Those are the three questions the brand name usually cannot answer.

Seiko — the 4R and NH families

The most widely used automatic architecture in affordable watches, and the only one that appears under two different names.

Seiko fits the 4R35 and 4R36 to its own watches and publishes their specification openly: automatic with hand winding, 24 jewels, 21,600 vibrations per hour, roughly 41 hours of power reserve, and an accuracy specification of about −35 to +45 seconds a day worn on the wrist. The 4R36 adds a day wheel; the 4R35 is date only.

The same design is sold to other brands through Seiko Instruments as the NH35 and NH36. That is why a $150 micro-brand diver and a Seiko 5 can share an engine — and why the difference between them is everything except the engine. Our NH35 versus 4R36 comparison goes through what actually separates them, which is mostly regulation and support.

Miyota — Citizen’s movement division

Citizen built a movement factory in the town of Miyota in Nagano in 1959, and launched the MIYOTA brand in 1980. By its own account its movements are used in millions of watches, and it is the second name you will meet constantly on affordable automatic listings.

The Miyota 9015 is the one enthusiasts care about, and Miyota publishes it in full: 24 jewels, 28,800 vibrations per hour, approximately 42 hours of running time, 3.90mm high, accuracy of −10 to +30 seconds a day, with a stop-second device and both automatic and hand winding.

Two things follow from those numbers. The higher beat rate gives a visibly smoother seconds sweep than the 21,600 vph Seiko calibers, and the 3.90mm height lets a brand build a genuinely thin watch. Our NH35 versus 9015 comparison covers the whole trade — the Seiko is tougher and cheaper to replace, the Miyota is finer.

ETA and Sellita — the Swiss supply

ETA

ETA SA of Grenchen is a wholly owned subsidiary of the Swatch Group and, historically, the company that supplied movement blanks to essentially the entire Swiss watch industry. Its vertical control over movement components made it enormously powerful.

In 2002 Swatch Group announced ETA would stop supplying non-Group competitors. Swiss regulators found that for movement blanks priced up to about $250 there were no real alternatives, and that the decision breached Swiss cartel law. ETA was ordered to keep supplying, and in 2012 authorities approved a phased reduction instead — 30% by 2015, 50% by 2017, 70% by 2019.

Sellita

That regulatory story is why Sellita matters. Based in La Chaux-de-Fonds and specializing in the assembly of Swiss Made automatic mechanical movements, Sellita moved from assembling for others to supplying its own SW-series calibers, which now appear across the independent Swiss industry.

Neither company’s movements appear in the price band this site covers, which is worth saying plainly: below about $700 you are almost always looking at a Japanese or Chinese caliber. The Swiss names are here because the question “who makes movements” is not answerable without them.

Sea-Gull, Hangzhou and the Chinese calibers

China builds movements at enormous volume, and the good ones are genuinely good. The best known is Sea-Gull’s ST1901, a hand-wound column-wheel chronograph with a long history that is the reason an affordable mechanical chronograph exists at all — every one on our chronograph roundup uses it, and none of them is automatic, which is the single most important thing to know about that category.

The ST16 automatic family is the other one you will meet, in budget watches from a long list of brands. It works. What is thinner than with Japanese calibers is documentation: published accuracy figures and service data are harder to find, so our spec tables print “Not published” more often on watches using them.

What “in-house” really means

In-house means the brand designed and built the caliber rather than buying it. Seiko, Citizen, Orient and Sea-Gull all genuinely do this, which is unusual at affordable prices and is a large part of why those brands are recommended so consistently.

What in-house does not mean is better. A specialist movement maker building millions of one caliber has advantages a small in-house operation does not, and a well-executed bought-in movement can outperform a bespoke one. In-house is a claim about origin. Treat it as information about supply chains and parts availability rather than as a quality grade.

The genuine practical advantage is support: a maker that builds its own calibers stocks its own parts and runs its own service network. That is why the same watch is easier to keep running for thirty years. Our service cost guide covers what that is worth in cash.

Three watches, three movement makers

The clearest way to see the difference is in real products. Three below, each built around a caliber from a different maker, with the published specification in each spec table. Prices come from a live daily check; we have not handled any of them.

How to identify the movement in a watch you already own

1. Check the listing or the manual. Seiko, Citizen, Orient and most serious brands name the caliber outright.
2. Look through the caseback. If the watch has an exhibition back, the caliber number is often printed on the rotor or on a bridge. NH35 movements are usually marked.
3. Match the behavior. A seconds hand ticking six times a second is 21,600 vph, which points at the Seiko family. Eight times a second is 28,800 vph, which points at the Miyota 9015 or a Swiss caliber.
4. If nothing names it, that is the answer. A brand that will not state its caliber is withholding the one specification that decides whether the watch can be serviced. Our micro-brand roundup treats a named caliber as a hard entry requirement for exactly this reason.