SEIKO Chrono SND640 Quartz Watch
Overview
The Seiko SND640 (7T92-0CW0) is a 38mm men's quartz watch with a stainless steel case and a black analog dial protected by hardlex crystal. It uses a 7T92 caliber quartz movement. The watch should run for up to 3 years before needing a new battery.
The SND640 is currently ranked #904 in popularity out of 1,137 watches in this catalog. No retailer link is on file for .com; current availability is unknown. You can see other models similar to this one on the left side of the page. By clicking the checkbox under a similar model you can compare that model with this one side-by-side. We use nearly 100 different weighted criteria to calculate which models are the most similar to one another.
SND640 is only a partial model number. [learn more]
The case of the SND640 measures approximately 38mm wide (not including the crown) by 10mm thick and is water resistant to 100 meters. This should be sufficient for splashes, rain, baths, showers & swimming (shallow diving) but is not recommended for scuba diving. The crown does not screw down which increases the risk that it could be pulled out accidentally while under water. The stainless steel bezel is fixed (cannot be rotated). The gap between the lugs is 18mm and the bracelet band can be adjusted to fit using a link removal tool or removed using a band removal tool to be replaced with another band.
Transform the look of this watch by adding an 18mm leather band such as a Hadley Roma, Hirsch or Crown & Buckle.
The SND640 provides the following features and complications:
- Second hand
- Seconds subdial
- Minute hand
- Hour hand
- Chronograph that includes subdials for hours, minutes and subseconds with a minimum resolution of 1/20 second and a maximum duration of 720 minutes. The central second hand is used by the chronograph. When the chronograph is not in use this hand is stationary. Seconds are shown on the seconds subdial.
- Date window to show the day of the month. Note that some watches may be damaged if you attempt to change the date between 8:00 PM and 2:00 AM, in which case you should change the time to be outside that range first then reset the time after adjusting the date. Check your watch manual for details.
Seiko Date Finder
If you have this watch and want to know when it was made simply enter the six digit serial number from the caseback below then click Find Date. Learn more
Specifications [edit]
Full specifications are listed below. Please report any errors by clicking the edit link above then use the appropriate 
icon to provide your input.
General
- Retailers No retailer link on file for .com
Search: Amazon | eBay | Chrono24 - Popularity
#904 of 1,137 - Style Chronograph
- Gender Men's
Movement
- Type Quartz
- Caliber 7T92
- Power Reserve 3 Years
- Hacking Yes
- Instructions Owner's Manual
Case
- Case Width
38mm(without crown) - Case Thickness 10mm
- Case Shape Round
- Case Material Stainless Steel
- Case Code 0CW0
- Crystal Material Hardlex
- Water Resistance 100 Meters(baths & shallow diving)
- Crown Position 03:00
- Screw Down Crown No
- Second Crown No
Complications
- Chrono Maximum 720 Minutes
- Chrono Minimum 1/20 of a Second
- Chrono Sub-Sec Yes
- Chrono Minutes Yes
- Chrono Hours Yes
- Second Hand Yes
- Seconds Subdial Yes
- Minute Hand Yes
- Hour Hand Yes
- Date Window Yes
Band
- Band Width 18mm
- Replaceable Band Yes
- Band Material Bracelet
- Band Color Gold
Dial
- Dial Color Black
- Dial Reference 0CY8
- Hour Markings Bars
- Subdial Position 6-9-12
- On the Dial
"Chronograph", Water Resistance
Bezel
- Bezel Color Gold
- Bezel Function Fixed
- Bezel Material Stainless Steel
- On the Bezel Nothing
Inner Bezel / Chapter Ring / Outer Dial
- Inner Bezel Color Black
- On Inner Bezel Tachymeter
Hand Colors
- Hour Hand Gold
- Minute Hand Gold
- Second Hand Gold
If you see anything that seems incorrect please let us know.
Back