The NH series of automatic movements are a long-time favorite base for custom builds by the Seiko modding community. However, while touted as a reliable workhorse caliber, these movements are prone to breakage if not handled correctly during the modding process itself. The pivots, wheels, and pinions used in any mechanical watch tolerate almost no sideload before bending or shearing.

As such, best practice advises always gripping NH movements by their edges, avoiding touching the fragile components on the front or back. A slip of the fingers can mean scratched jewels or detached winding stems and hours of remedial work, if you can do it. 

This fragility is where movement holders enter the equation - simple devices made to securely cradle and position movements while modding. They provide cheap insurance against mishaps caused by a bad grip or positioning using bare hands. However, not everyone agrees they are mandatory. In this article, we’ll examine the case for (and against) using dedicated movement holders when modding Seiko watches.

What Is a Movement Holder?

A movement holder is specially designed and made to securely grip a specific mechanical watch movement. It acts as an extra set of hands, holding the movement in an optimal position so that both of your hands are free to work. Movement holders typically feature rounded indentations, notches, or foam pads to hold all sides of the movement without placing too much localized pressure at any point. Many have dedicated cutout slots that allow you to pull the stem and crown through or to fasten the hands without needing tweezers or steady fingers. They enable you to tilt the movement any which way to inspect each bridge, wheel, and jewel while maintaining a safe, stable grip.


Source: @rusty_watches on IG


Contrast this with the all too common practice of using your fingers and hand to directly hold onto a movement while attempting awkward mods. It simply lacks the same level of security and control. Slip-ups here can mean damage that may render your brand new movement useless. Not exactly an ideal outcome. It’s not hard to understand why many watchmakers strictly rely on dedicated movement holders in their work.

Why Use a Movement Holder

There are several clear benefits to using a proper movement holder when doing Seiko mods:

  1. It holds the movement completely motionless so there is little chance of it slipping while applying pressure. Tiny parts like balance springs are extremely fragile against shearing forces. One errant slip of a hand and things can go downhill fast. Mounted securely, this risk goes away.
  2. Both hands are freely available to handle small parts, grip tiny screws, or position components. Very few of us have watchmaker-style dexterity using just fingertips. Removing the stress of keeping hold of the movement makes precise work much easier.
  3. The movement receives uniform pressure from all sides within the padded watch holder instead of uneven stresses. This prevents distortion that alters mechanical clearances.
  4. Angled indentations allow you to inspect the movement from multiple useful angles while limiting the need to touch or squeeze delicate components. Loupes also integrate better when hands-off.

Why Some are Against It

Of course, the opposing view also has reasonable backing. Plenty of expert modders skip the dedicated movement holders with good justification:

  1. They add incremental cost that you may otherwise use for a different modding part.
  2. Many argue that Seiko movements are purpose-built to withstand reasonable hand winding and hacking pressures from daily wear. Their robust construction gives more leeway for incidents.
  3. Direct finger pressure allows better "feel" to catch winding grittiness or hitches that indicate issues. These subtle symptoms are missed with padded holders.
  4. Positioning the movement on a foam surface and working around stable edges can achieve a reasonably slip-free platform without needing to buy any extra parts. Adapting this skill just takes practice.
  5. As loupes zoom tighter, working at sharp angles becomes easier by rotating the whole body rather than just contorting wrists. Veteran watchmakers can more comfortably work on movements when held by hand.
  6. Some watchmakers caution that certain holder materials leave microscopic abrasions on highly polished movement finishes if shifting forcefully across them repeatedly.

If You Need It, We Have It

Now that you know both sides of the argument, it’s up to you to decide if you have trust in your hand-eye coordination and prefer to directly handle the movement while modding, or if you want to be more cautious and invest in a movement holder. If you are of the latter school of thought, you can check out our collection of 3 slick movement holders in brushed, gunmetal, or rainbow finish.

And don’t forget that you get 50% off the price of movement holders if you are also buying a case together with it. No code needed, just add the necessary items to your cart!


As with most skill-based endeavors, there are multiple schools of thought around the "right" way of doing things. Consistency, care, and patience tend to trump specific tools as experience accumulates.

Given the tricky balance, reasonable arguments exist on both sides of whether mandatory movement holders are essential tools for Seiko mods. Enthusiasts should explore costs and alternatives before deciding to purchase specialty equipment versus training finger dexterity.

Regardless of your experience level, patience is your friend when handling intricate mechanical calibers. While not strictly necessary for everyone, dedicated movement holders provide inexpensive insurance against a rushed job leading to heartache down the road.

Happy modding!
February 24, 2024 — Jeremiah A

Leave a comment

Please note: comments must be approved before they are published.