What Is an NH35 Movement? And Why Is It Used in So Many Automatic Watches?

If you’ve spent any time looking at automatic watches, especially independent brands, microbrands, or custom builds, you’ve probably seen the letters NH35.

It shows up everywhere.

There’s a reason for that.

The NH35 is a mechanical automatic movement made by TMI, part of the Seiko group, and it has become one of the most widely used movements in affordable automatic watches.

For JMR, it also happens to be one of the movements I use most often.

First: what is an automatic movement?

An automatic watch doesn’t use a battery.

Inside the watch is a mechanical movement powered by a mainspring. As you wear the watch, a weighted rotor moves with your wrist and winds that spring.

You can also wind many automatic watches by hand using the crown.

Once wound, the movement slowly releases that stored energy to run the hands and keep time.

There’s something I like about that.

A mechanical watch is a tiny machine sitting on your wrist, constantly working without needing to be plugged in or have a battery replaced.

So what exactly is the NH35?

The NH35 is a Japanese automatic movement known for being simple, dependable, and easy to service or replace.

It includes the things most people actually want in an everyday mechanical watch:

• Automatic winding
• Hand winding
• Hacking seconds
• Date function
• Approximately 40 hours of power reserve
• 24 jewels

Hacking seconds simply means the seconds hand stops when you pull the crown out to set the time.

That lets you set the watch more precisely.

Why do so many watchmakers use it?

The NH35 hits a useful middle ground.

It’s affordable enough to use in smaller independent builds, but it has a strong reputation for reliability.

That matters when you’re building watches in small numbers.

I’d rather put money into a good case, sapphire crystal, bracelet, dial, hands, and finishing than use an unnecessarily expensive movement just because the name sounds impressive.

The NH35 allows me to do that.

It also has another major advantage:

parts availability.

Because the movement is so widely used, there are an enormous number of compatible cases, dials, hands, and components available.

That makes it especially useful for custom watches and one-off builds.

Is the NH35 a luxury movement?

Not really.

And that’s okay.

It isn’t trying to be.

The NH35 is more like a dependable engine than an exotic one.

There are movements with higher beat rates, more decorative finishing, thinner construction, longer power reserves, and tighter factory accuracy.

They also tend to cost significantly more.

The NH35's appeal is that it does its job well and has been doing it for years.

For a watch meant to be worn regularly, that’s a pretty good starting point.

How accurate is an NH35?

Mechanical watches are not as precise as quartz watches.

That’s true whether the mechanical movement costs $50 or several thousand dollars.

The NH35 is generally rated by the manufacturer to operate within a fairly broad daily accuracy range, although individual movements can often perform better than that.

A watch may gain or lose a handful of seconds throughout the day depending on things like position, temperature, movement regulation, and how much it has been worn.

For most owners, that’s simply part of owning a mechanical watch.

Why I use the NH35 at JMR

For me, the movement fits what JMR is about.

I'm not trying to build watches around a movement specification sheet.

I'm trying to build watches around a story.

The movement needs to be dependable, serviceable, and capable of doing its job without becoming the entire reason the watch costs what it does.

The NH35 lets me focus on the parts you'll actually see and interact with every day.

The dial.

The case.

The hands.

The bracelet.

And most importantly, the idea behind the watch.

JMR watches powered by the NH35

Several JMR builds use the NH35, including watches such as Pin High, Lake Effect, Night Watch, Blue Steel, and The Sunday Pin.

They all use the same basic mechanical engine.

But they couldn't look much more different.

That's one of the things I enjoy most about building watches.

You can start with the same movement and end up with something inspired by golf, a West Michigan winter, late nights with a newborn, or just a really good-looking square watch.

The movement makes the watch run.

The story makes it JMR.