Seiko Caliber Ne20c

SII (Seiko Instruments) Caliber NE20

Seiko Caliber Ne20a Drawing

ManufacturerSeiko Instruments (SII)
Caliber NumberNE20, NEW20A
Base Caliber
Movement TypeAutomatic
Casing Diameter
Vibrations Per Hour
28,800 bph
Lift Angle
52 degrees
Power Reserve
~45 hours
Hand Windable?Yes
Winding Direction
Anti-Shock System
Seiko Diashock
Regulator System
Hand Sizes
1.50mm / .89mm / .21mm
FunctionsCentral hours; central minutes; central sweeping seconds; day of the week hand at 3:00; date hand at 6:00; power reserve indicator at 9:30
Country of ManufactureJapan
Known Models
Aragon Enforcer Power Reserve, Invicta Ocean Predator (Add your watch in the comments below…)

The Seiko caliber NE20 is a movement produced by Seiko Watch Corp. in their Seiko Instruments/Time Module branch. Tech docs for this caliber were found dated as far back as May 2010, so this movement has been around for at least that long.

Seiko Caliber Ne20c

Caliber NE20 VS NE20A, NE20B, NE20C:

The letter at the end of NE20* indicates an evolution of the NE20 (NE20A, NE20B, NE20C, etc). The official tech sheets for the caliber NE20C were updated on December 14, 2021. The differences between each iteration is unconfirmed. If you have insight into this, please comment below.

Seiko Instruments NE20 VS Seiko 6R21:

The Seiko caliber 6R21 (6R21A, 6R21B) is basically a Seiko-only version of the NE20 (NEW20A, NE20B, NE20C). Seiko Instruments/Time Module (aka SII/TMI) sells the NE20 to other manufacturers (such as microbrands) for use in non-Seiko watches.

NE20 Accuracy:

Seiko claims that the accuracy of caliber NE20 is between -15/+25 seconds per day. This rating is based on normal daily wear on the wrist in normal operating temperatures.Seiko tests the accuracy in 3 positions: dial up, crown down (9:00 up), and crown left (6:00 up). When testing your watch for timekeeping, make sure it is fully wound (see below).

Power Reserve:

The caliber NE20 holds a power reserve of greater than 45 hours. To fully wind the mainspring, turn the crown a minimum of 55 times. There is a power reserve indicator located at 9:30 on the dial.

Crown Position Functions:

0 (against the case): Clockwise = Manual Winding / Counterclockwise = Nothing
1 (pulled out one click): Clockwise = Day setting / Counterclockwise = Date setting
2 (pulled out two clicks): Time setting clockwise and counterclockwise

Stem Removal:

To remove the stem, make sure the crown is in position 0 or normal position (not date or time setting position). There is a lever with a small indentation for your tool. Gently press down while pulling the stem out. See official instructions below for more guidance:

Seiko Caliber 4r36 Stem Removal

Replacement Price:

At the time of this post, prices for replacement NE20 movements were found online for $285.00 to 388.95 USD.

Does Miyota make a similar movement?

See the Miyota 9132 caliber listing.

Additional Resources:
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List of Seiko Watch Movements Watch Movement | Caliber Corner
11 months ago

[…] NE20 […]

Ronald Walters
Ronald Walters
8 months ago

I have an Aragon Enforcer Limited Edition with this movement. It’s the most accurate in my collection and my favorite

5 months ago
Reply to  Ronald Walters

I love my ne20 watches. I just got that model and color and anxiously awaiting delivery.
These movements are top tier IMO. Very accurate , high-beat as well as robust and reliable.

2 months ago

I have the Aragon ConceptS Limited Edition with the NE20B w/29 jewels & this movement is one of my favorites in my collection with day/date & power reserve…

Venus Caliber 178
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