IDENTIFY UNKNOWN MARKS
Found a marking on your watch that you don't recognize? You're not alone. Watches carry a wide variety of stamps, engravings, and codes that indicate everything from the manufacturer and model to the case material and water resistance rating. Browse by category below or scroll through our full index of identified markings.
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Watch Back Marks
Engravings, stamps, and codes found on the case back of watches — serial numbers, logos, material stamps, and more.
Bracelet Marks
Markings found on watch bracelets and clasps — brand codes, material indicators, and manufacturing stamps.
Case Marks
Stamps and engravings found on watch cases — between the lugs, on the case side, or inside the case.
Movement Marks
Markings found on watch movements — caliber numbers, jewel counts, country of origin, and regulation marks.
Water Resistance
Water resistance ratings and symbols — meters, BAR, ATM, and what each level actually means for real-world use.
Country of Origin
Origin stamps like Swiss Made, Japan Movt, Made in Japan, and German Made — what they legally signify.
ALL WATCH MARKINGS
Serial Number Engraving
A unique alphanumeric code engraved on the case back that identifies your individual watch. This number is typically used for warranty registration, service history, and authentication.
Model Number Stamp
An alphanumeric code stamped on the case back that identifies the specific watch model or product line. This number is essential for ordering replacement parts and identifying your watch's specifications.
Water Resistance Rating (Case Back)
A marking indicating the watch's tested water resistance depth, typically shown in meters, feet, bar, or ATM. This rating describes laboratory test conditions, not actual diving depth recommendations.
Case Material Marking
An engraving or stamp indicating the material the watch case is made from, such as stainless steel, titanium, or gold. This marking helps verify authenticity and informs care and maintenance decisions.
Crystal Press Back Symbol
A small symbol on the case back indicating it should be opened with a crystal press tool rather than unscrewed. This marking guides watchmakers on the correct method for case back removal.
Japan Movement Stamp
A case back marking indicating the watch uses a movement manufactured in Japan. This is commonly seen as "JAPAN MOVT" or "JAPAN MOVEMENT" and denotes the origin of the caliber inside.
Stainless Steel Back Stamp
A marking reading "STAINLESS STEEL BACK" or "ST. STEEL BACK" indicating the case back material. This is commonly found on watches where only the back is stainless steel while the case body may be a different material.
Clasp Code Stamp
An alphanumeric code stamped on the bracelet clasp identifying the clasp model and sometimes the production date. This code helps identify replacement clasps and can aid in dating the bracelet.
Bracelet End Link Number
A number stamped on the end links of a bracelet identifying their specific shape and size. This number is critical for finding replacement end links that properly fit your watch case.
Deployment Clasp Marking
Markings found on a deployment (deployant) clasp that identify the clasp type, size, and brand. These help determine compatibility when replacing or servicing the clasp mechanism.
Bracelet Model Number
A unique identifier stamped on the bracelet that specifies the exact bracelet model. This number is essential for ordering correct replacement bracelets or links.
Adjustable Clasp Indicator
Markings or features on a clasp indicating it has micro-adjustment or on-the-fly sizing capability. This allows fine-tuning of bracelet fit without tools.
Case Reference Number
A manufacturer-assigned reference number identifying the specific watch case design, dimensions, and material. This is the primary identifier for sourcing correct case parts and compatible accessories.
Lug Width Marking
A number stamped between or on the lugs indicating the distance between them in millimeters. This measurement determines which strap or bracelet width fits your watch.
Bezel Insert Code
A code identifying the specific bezel insert installed on a watch, typically relevant for dive watches and GMT models. This number is essential for sourcing correct replacement inserts.
Crown Logo Stamp
A brand logo or emblem stamped or engraved on the watch crown. This identifies the manufacturer and can indicate whether the crown is an original or replacement part.
Case Size Indicator
A marking indicating the watch case diameter or dimensions, typically in millimeters. This helps identify the watch model variant and determine strap compatibility.
Caliber Number
A manufacturer's identifier for the specific movement (mechanism) inside the watch. This number reveals the movement type, features, accuracy, and service requirements.
Jewel Count Marking
A marking indicating the number of jewels (synthetic rubies) used as bearings in the movement. This number reflects movement complexity but is not a direct indicator of quality.
Movement Country of Origin
A marking indicating where the watch movement was manufactured, such as "Swiss" or "Japan." This identifies the movement's origin, which often influences perceived quality and value.
Regulation Marking
Markings on or near the movement's regulator indicating adjustment positions for timing accuracy. These are used by watchmakers to fine-tune the watch's rate.
Shock Protection Symbol
A marking indicating the movement incorporates a shock protection system for the balance wheel. Common systems include Incabloc, Diashock, and Parashock.
WR 50M / 5 Bar Marking
A water resistance rating of 50 meters (5 bar/ATM), indicating the watch can handle everyday moisture like rain and hand washing. This rating is not suitable for swimming or submersion.
WR 100M / 10 Bar Marking
A water resistance rating of 100 meters (10 bar/ATM), generally considered suitable for swimming and recreational water activities. Not rated for scuba diving or high-impact water sports.
WR 200M / 20 Bar Marking
A water resistance rating of 200 meters (20 bar/ATM), suitable for serious water sports and recreational scuba diving. This is the standard entry-level rating for purpose-built dive watches.
Bar / ATM Pressure Rating
A water resistance rating expressed in bar or ATM (atmospheres) instead of meters. One bar/ATM approximately equals 10 meters of water depth in testing pressure.
Swiss Made Label
A legally protected designation indicating the watch meets Swiss origin requirements for movement, assembly, and quality inspection. "Swiss Made" is one of the most recognized quality marks in watchmaking.
Japan Movt Marking
A case back marking indicating the watch uses a Japanese-manufactured movement. This is one of the most common markings found on affordable watches worldwide.
Made in Japan Stamp
A marking indicating the watch was fully assembled in Japan, not just the movement. This designation is particularly valued on Seiko, Citizen, and Orient watches for the domestic Japanese market.
German Made Marking
A marking indicating the watch was manufactured in Germany, typically associated with brands from the Glashutte or Pforzheim watchmaking regions. German watches are known for Bauhaus design and engineering precision.
Kanji Case Back Inscription
Japanese characters (kanji or katakana) engraved or printed on the case back of watches sold in Japan. These inscriptions typically convey model names, material descriptions, or brand text written in Japanese.
JDM Model Reference Code
A model reference number specific to the Japanese domestic market that differs from the international version. JDM codes often follow unique formatting conventions, such as Seiko's alphanumeric SBDC or SARB prefixes.
PSC Diamond Safety Mark
A small diamond-shaped symbol required on consumer products sold in Japan under the Product Safety of Consumer Products Act. On watches, it confirms compliance with Japanese electrical and safety standards.
Domestic Market Dial Text
Japanese text printed on watch dials indicating features or specifications in the domestic language. Common examples include characters for water resistance, automatic winding, or material type on JDM-exclusive models.
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