Counterfeit Casio watches are widespread, and the F-91W is no exception.
Although counterfeit F-91W watches offer low profit margins, the risk of being identified and reported is also low. As a result, there are plenty of listings on e-commerce platforms for around $10. Although they may perform almost identically in everyday use, a genuine watch costs only around $21.
Some of the identification methods previously published online are no longer applicable as counterfeit manufacturers continue to improve their production capabilities. I have compiled these methods here for reference.
The most reliable way to authenticate a watch is undoubtedly to remove the case back and inspect the movement. However, since most authentication checks are conducted remotely, I will not cover this method here.
There’s no need to save just $10 by buying a counterfeit product. You can confidently purchase this genuine watch on Amazon.
1. Long press the right button, and the word “CASIO” will appear on the display. Counterfeit versions already have this feature. — Software technology
2. Press all three buttons simultaneously to display all segments on the screen. Counterfeit versions already have this feature. — Software technology
3. The buzzer sounds different, and there seems to have been some improvement. It is difficult to identify the difference without a direct comparison. Remove the case back and inspect the piezoelectric buzzer. Genuine watches have printed markings on the buzzer, while counterfeit watches do not. — Hardware technology
4. Counterfeit watches do not keep accurate time, but this is difficult to identify over a short period. — Hardware technology
5. Case back: On genuine watches, the inscriptions are clear and evenly formed, and the metal surrounding the inscriptions has no dents. The case back is flat overall. Counterfeit watches use a stamping process. Due to the precision of the mold and the manufacturing method, the lettering may have uneven strokes, and the metal surrounding the inscriptions may become deformed. This is a key point to check when identifying counterfeits. Counterfeit manufacturers are unlikely to improve this aspect because of cost considerations. — Hardware technology
6. Display: Observe the digits under a single light source. Counterfeit watches have shadows around the digits, making them appear doubled and causing visual discomfort. Genuine watches have very little shadowing, and the digits appear clear and evenly displayed.
On older counterfeit movements, viewing the display from an angle, such as from the side, would cause all the digits to show 8888 across the screen. This is an important point to check. Counterfeit manufacturers are unlikely to improve this feature on the F-91W because of the need to balance movement technology and the cost of the finished product. — Hardware technology
7. Screws: On genuine watches, the screw heads are flat and thin, measuring approximately 20% of the height of the case back, with flat ends. On counterfeit watches, the screw heads are thicker, measuring approximately 80% of the height of the case back, and have pointed ends.
This may be because the molds used to manufacture counterfeit watch cases are not precise enough, making thread tapping necessary to ensure proper screw installation. — Hardware technology
8. Other details: Buckle components and dial printing are not consistent across counterfeit versions because there are many different variants. Since counterfeit products are inexpensive to manufacture, these details can also be improved relatively easily. Therefore, they are not key identification criteria and are mentioned here only as limited examples. — Hardware technology
Overall conclusion: Software improvements are inexpensive, while hardware improvements are costly. For a genuine Casio watch that costs only around 90 yuan, the scope for counterfeit manufacturers to make further improvements is limited. There is no need for anyone to buy counterfeit watches, and this is precisely why I am publishing this post.
