The Seiko 7S26 movement was introduced in 1996 as a replacement for the 7002 movement. It quickly became the go-to movement for many of Seiko’s entry-level automatic watches, particularly the popular Seiko 5 series.

The 7S26 is known for its rugged construction and reliability, making it a favorite among both new and seasoned watch collectors. In this blog, we’ll dive into more details of this movement, and Seiko 7S26 vs Seiko NH35 movement.

• Movement Type: Automatic
• Accuracy: -20 to +40 seconds per day
• Frequency: 21,600 vibrations per hour (vph)
• Jewels: 21
• Power Reserve: 41 hours
• Height: 4.80 mm
• Diameter: 27.4 mm
• Hacking: No
• Hand-Winding: No
• Date Function: Yes (Day/Date)

Differences Highlighted:

• Jewels: The NH35 movement has 24 jewels compared to the 21 jewels in the 7S26.
• Height: The NH35 is slightly thicker at 5.32 mm compared to the 4.80 mm height of the 7S26.
• Hacking and Hand-Winding: The NH35 includes both hacking and hand-winding features, which are not present in the 7S26.
• Date Function: The 7S26 has a day/date function, whereas the NH35 has only a date function.

Here is a comparison chart of this two movement:

The Seiko 7S26 movement is used in various iconic Seiko models, especially within the Seiko 5 series. Some known models include:

• Seiko SKX007: This popular dive watch is famed for its durability and classic design, powered by the 7S26.
• Seiko SNK809: A beloved field watch that combines military aesthetics with the reliable 7S26 movement.
• Seiko SNZF17: Often referred to as the “Sea Urchin,” this model is another example of the 7S26’s robust performance in an affordable package.

Setting the time on a watch powered by the Seiko 7S26 involves:

1. Pull the crown out to the second position.
2. Turn the crown to set the time.
3. Push the crown back in to start the movement.

The Seiko 7S26 is a non-hacking and non-hand-winding movement, relying solely on automatic winding.

It features a bi-directional winding system and incorporates 21 jewels to minimize friction. The movement’s 21,600 vph frequency ensures a smooth motion of the second hand, and the 41-hour power reserve provides ample running time.

The average replacement price for a Seiko 7S26 movement ranges from $40 to $60, making it an affordable choice for both new and replacement movements in entry-level automatic watches.

While the Seiko 7S26 is highly regarded, it has a few shortcomings:

• No Hacking or Hand-Winding: The absence of these features may be a drawback for those who prefer precise time-setting and manual winding capabilities.
• Thickness: Compared to more modern movements, the 7S26 is relatively thick, which may limit its use in slimmer watch designs.

Here is a review from Watchuseek forum

“The 7S26 in my Seiko 5 is a workhorse. It’s not the prettiest movement, and the lack of hacking can be annoying, but it keeps ticking no matter what. I appreciate its robustness and low maintenance.”

The Seiko 7S26 is a testament to Seiko’s commitment to producing reliable and affordable automatic movements. Despite its lack of modern features like hacking and hand-winding, the 7S26 remains a favorite among watch enthusiasts for its robustness and longevity.

When compared to the Seiko NH35, the 7S26 holds its own in terms of affordability and reliability, though the NH35 offers additional features that might appeal to those looking for more precise time-setting capabilities.