PSC Diamond Safety Mark — What This Mark Means
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.
What This Usually Means
The PSC (Product Safety of Consumer) diamond mark is a mandatory safety certification for certain consumer products sold in Japan. On watches, it typically applies to models with lithium batteries or other regulated components. The diamond shape contains specific characters indicating the product category and certifying that it meets Japanese safety requirements established by the Ministry of Economy, Trade and Industry.
Where to Find It
The PSC diamond mark is usually found on the case back, often small and positioned near other regulatory markings. It typically appears as a tiny diamond-shaped outline containing Japanese characters. On quartz watches, it is commonly located near the battery information or alongside other compliance symbols.
Advertisement
Common Variations
The diamond mark may vary slightly in size and detail depending on the product category. Some watches display only the diamond outline with minimal internal markings, while others include the full PSC designation. The mark sometimes appears alongside other Japanese regulatory symbols such as the Technical Conformity Mark for radio-equipped watches.
Common Misconceptions
Many collectors outside Japan mistake the PSC diamond for a brand logo, quality grade, or decorative element. It is strictly a regulatory compliance symbol and does not indicate premium quality or special status. Its presence simply confirms the watch was legally sold in the Japanese market and met applicable safety standards at the time of sale.
What to Do Next
If you see this mark, it confirms your watch was produced for or sold in the Japanese domestic market. Look for other JDM indicators such as kanji text, a JDM model reference number, or Made in Japan dial markings. The PSC mark itself does not require any action but helps authenticate the watch's Japanese market origin.
Advertisement
Related Markings
A case back marking indicating the watch uses a movement manufactured in Japan. This is commonly seen as "JAPAN MOVT" or
Made in Japan StampA marking indicating the watch was fully assembled in Japan, not just the movement. This designation is particularly val
Kanji Case Back InscriptionJapanese characters (kanji or katakana) engraved or printed on the case back of watches sold in Japan. These inscription
JDM Model Reference CodeA model reference number specific to the Japanese domestic market that differs from the international version. JDM codes
Domestic Market Dial TextJapanese text printed on watch dials indicating features or specifications in the domestic language. Common examples inc
Commonly Seen On
Related searches
Frequently asked questions
What is the small diamond symbol on my watch case back?
It is most likely the PSC (Product Safety of Consumer) diamond mark, a Japanese regulatory symbol required on certain consumer products sold in Japan.
Does the PSC diamond mark indicate quality?
No. It is a mandatory compliance symbol confirming the product meets Japanese safety standards. It does not serve as a quality grade or endorsement.
Why do some non-Japanese brands have this mark?
Any watch sold in Japan that falls under PSC regulations must carry this mark, regardless of the brand's country of origin. International brands like Tissot display it on models sold in Japan.
Can I tell if my watch is JDM from this mark alone?
The PSC mark strongly suggests the watch was intended for the Japanese market. However, confirming JDM status typically requires checking additional indicators like the model reference and dial markings.
Is the PSC mark the same as JIS certification?
No. The PSC mark relates to product safety under consumer protection law, while JIS (Japanese Industrial Standards) certification relates to quality and manufacturing standards. They are separate systems.
Does every watch sold in Japan have this mark?
Not necessarily. The PSC mark is required for specific product categories that include components like lithium batteries. Purely mechanical watches without regulated components may not require it.