Looking for a watch that lasts a lifetime—or even long enough to pass down? Choosing a durable, repairable, and accurate timepiece isn’t just about style; it’s…
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The Casio F-91W is a classic digital watch known for its reliability, simplicity, and exceptional value. First introduced in the late 1980s, it has earned a reputation for durability and longevity far beyond its modest price. Its quartz movement maintains accuracy within ±30 seconds per month, and the 7-year CR2016 battery keeps it running for nearly a decade before needing replacement—easily done at home with a small screwdriver. For many owners, that combination of accuracy and low maintenance makes it a daily-wear watch that can last decades with care.
While its resin case and acrylic crystal are prone to scratches compared to stainless steel or sapphire models, the F-91W remains remarkably tough for everyday use. It’s rated for day-to-day water resistance (splash-proof, not swim-proof) and has a legible LCD display with a one-sided LED backlight—functional, though dim in low light. The simple design also makes it highly repairable: replacement straps, gaskets, and batteries are widely available, and online guides walk users through basic servicing.
Casio backs the F-91W with a 1-year limited warranty covering defects in materials and workmanship. While coverage excludes wear-and-tear parts like the band and glass, the warranty terms are transparent and supported by accessible service centers. In short, the F-91W isn’t heirloom-grade in materials, but it’s a long-lasting, easily maintained timepiece—a true workhorse that often outlasts far pricier watches.
Casio is one of Japan’s most enduring tech brands, known for turning everyday tools into reliable, long-lasting companions. Founded in 1957, the company built its reputation on precision engineering and inventive design—from the first digital watches to today’s solar-powered and Bluetooth-connected timepieces. Casio’s guiding principle of “Creativity and Contribution” emphasizes creating original, useful products that stand the test of time, a philosophy reflected in its G-Shock line—widely praised for durability, water resistance, and real-world toughness.
The company’s sustainability efforts go beyond slogans. Casio is a long-time member of the UN Global Compact and follows ISO 26000 social responsibility standards, signaling a structured commitment to ethical and environmental goals. While its mission statements focus more on innovation and user enjoyment than explicit repairability, Casio’s longevity as a brand—publicly listed, financially stable, and continuously innovating—suggests a solid foundation for long-term product support.
Shoppers who value dependable, low-maintenance watches and accessible technology often see Casio as a trustworthy choice. From the indestructible G-Shock to minimalist analog models, the brand’s strength lies in making well-engineered, affordable devices that consistently deliver durability and reliability decade after decade.
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Mission & Values
Whether the brand explicitly commits to durability, repairability, and sustainability.
Ideal: Brand mission and actions clearly prioritize long-lasting, repairable products.
Confidence —
MEDIUM
3 sources
65.0%
(W 40%)
PRO
:contentReference[oaicite:0]{index=0} articulates a clear Purpose: “Through the power to put wonder at hand, bring new levels of joy to lives one by one.” Their corporate creed “Creativity and Contribution” emphasises creating original, useful products and contributing to society, which aligns with long-term product value. They have formal sustainability frameworks: membership of the UN Global Compact (since 2010) and using ISO 26000 guidance, indicating mature commitment.
CON
While sustainability and social responsibility are emphasised, there is less explicit language about **repairability** or **long-life product support** in their public mission statements.The mission and values focus more on innovation and creativity than on durable/heirloom product design or repair infrastructure being central.
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Track Record / Reputation
Independent history of reliability and consumer trust.
Ideal: Decades of consistent positive reputation from reviews, watchdogs, and experts.
Confidence —
MEDIUM
3 sources
70.0%
(W 40%)
PRO
Casio has been manufacturing watches since the company’s establishment in 1957 and has sustained global presence in timepieces for decades. Reviews of the G-Shock line praise its durability in harsh conditions (resin case, 200 m water resistance, minimal wear) indicating strong real-world performance.
CON
Some customer-service reviews (e.g., via Trustpilot) cite issues with support, repair cost and warranty clarity, which may affect perceived reliability of after-sales experience. While product durability is widely praised, less third-party detailed analysis is available on long-term repairability and spare-part availability for all Casio watch models.
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Corporate Stability
Financial and organizational stability of the brand or company.
Ideal: Established, stable company with low risk of discontinuing support.
Confidence —
HIGH
3 sources
80.0%
(W 20%)
PRO
Casio Computer Co., Ltd. is publicly listed, founded in 1957, with net sales ~¥261,757 million and 8,801 employees (as of March 31, 2025) — indicating substantive size and long-term operations. Casio maintains structured corporate governance with risk-management and business-continuity planning (e.g., Crisis Management Manual, business continuity task force) suggesting resilience.
CON
Recent reporting (via third-party sources) points to a ransomware attack disrupting earnings in 2024, which could indicate exposure to operational risk. Some business segments (e.g., electronic dictionaries) are being scaled back, implying the need for Casio to pivot—though watches remain a core business.
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Coverage
Scope of what failures the warranty covers.
Ideal: Full coverage of defects and workmanship, including all major components.
Confidence —
HIGH
2 sources
40.0%
(W 20%)
PRO
Covers defects in quality/workmanship for the product during the warranty period.Casio will repair or replace with reconditioned parts/models for valid claims.
CON
Consumables and limited-resistance items (battery, band, case, glass) are excluded.Damage from misuse, improper repair, fire/natural calamity is excluded.
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Duration
Length of warranty term.
Ideal: ≥10 years (lifetime where feasible).
Confidence —
HIGH
2 sources
10.0%
(W 30%)
DATA
1 year
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Ease
How simple it is to file and process a warranty claim.
Ideal: Clear online or phone process requiring minimal effort or paperwork.
Confidence —
HIGH
1 sources
40.0%
(W 10%)
PRO
Published phone numbers and service center process are provided.Can take or send the watch to a Casio Service Center or the retailer with proof of purchase.
CON
Customer must ship the watch postage paid and is advised to insure the package.Requires proof of purchase and may involve mailing logistics.
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Cost
Direct costs to the customer for warranty service.
Ideal: No cost to the customer, including free shipping and parts.
Confidence —
HIGH
1 sources
60.0%
(W 10%)
DATA
$0 parts/labor; customer pays shipping
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Exclusions
Limitations or carve-outs in warranty terms.
Ideal: Few or no exclusions; coverage applies to all core components.
Confidence —
HIGH
1 sources
30.0%
(W 10%)
PRO
Standard defect coverage is clearly defined.
CON
Battery, band, case, and glass are excluded from coverage.Improper treatment and non-authorized repairs void coverage.
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Transparency
Clarity and accessibility of warranty wording.
Ideal: Plain-language warranty document published openly online.
Confidence —
HIGH
2 sources
80.0%
(W 10%)
PRO
Warranty details published on Casio's website and as a downloadable PDF.Key terms like duration, exclusions, and claim steps are stated plainly.
CON
Coverage varies by country of purchase, which may add some ambiguity.
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Transferability
Whether warranty transfers to subsequent owners.
Ideal: Warranty fully transferable between owners with no loss of coverage.
Confidence —
HIGH
1 sources
10.0%
(W 10%)
DATA
Non-transferable (original purchaser only)
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Case Material Hardness
Resistance of the watch case to scratches, dents, and daily wear.
Ideal: High-grade stainless steel, titanium, or ceramic with proven scratch resistance ≥1200 HV.
Confidence —
HIGH
1 sources
20.0%
(W 25%)
DATA
Resin case (no hardness rating provided)
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Crystal Scratch Resistance
Ability of the watch glass to resist scratches and impacts.
Ideal: Sapphire crystal or equivalent hardness ≥9 on the Mohs scale.
Confidence —
HIGH
3 sources
20.0%
(W 25%)
DATA
Resin Glass (acrylic) ≈ 3–4 Mohs
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Water Resistance Rating
Depth pressure the watch can withstand without water ingress.
Ideal: ≥100 m (10 ATM) water resistance for everyday and sport use.
Confidence —
HIGH
1 sources
25.0%
(W 20%)
DATA
Day-to-day Water Resistant (no depth rating stated on product page)
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Movement Lifespan
Expected operational life of the internal movement before major servicing.
Ideal: Mechanical or quartz movement rated for ≥10 years before overhaul.
Confidence —
LOW
0 sources
0.0%
(W 30%)
DATA
—
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Serviceability of Movement
Ease of accessing and servicing the movement for cleaning or part replacement.
Ideal: Standardized or modular movement with published service guides and compatible tools.
Confidence —
MEDIUM
1 sources
70.0%
(W 30%)
PRO
4-screw back provides straightforward access.Multiple step-by-step public guides exist for opening the case and servicing/replacing parts.
CON
Care required to preserve gasket and small parts; not officially user-serviceable by Casio.
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Spare Parts Availability
Availability of genuine replacement parts such as crystals, gaskets, and crowns.
Ideal: Manufacturer or third-party suppliers offer all critical parts for ≥10 years after production.
Confidence —
MEDIUM
3 sources
65.0%
(W 35%)
PRO
Genuine replacement bands and parts are widely sold by authorized parts retailers.Multiple third-party sources list F-91W specific components.
CON
Official Casio storefront does not centrally list all small parts for F-91W (availability varies by retailer).
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Battery or Power Source Replacement
Ease and cost of replacing or recharging the power source.
Ideal: User-replaceable battery or self-winding mechanism with accessible servicing instructions.
Confidence —
HIGH
2 sources
90.0%
(W 20%)
PRO
Uses standard CR2016 cell with published 7-year life.User-replaceable with basic tools; widely documented guides available.
CON
Opening the case risks compromising water resistance if gasket is not seated correctly.
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Strap and Lug Compatibility
Ease of replacing or upgrading the watch strap or bracelet.
Ideal: Standard lug widths (18–22 mm) with tool-free spring bars or quick-release pins.
Confidence —
MEDIUM
2 sources
50.0%
(W 15%)
DATA
18 mm lug width; factory attachment uses fixed pins (not standard spring bars)
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Timekeeping Accuracy
Precision of timekeeping under normal conditions.
Ideal: Accuracy within ±15 seconds/month (quartz) or ±5 seconds/day (mechanical).
Confidence —
HIGH
1 sources
60.0%
(W 35%)
DATA
±30 seconds/month
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Power Reserve Duration
Time the watch runs from full charge or winding until stopping.
Ideal: ≥48 hours for mechanical; ≥2 years for quartz battery life.
Confidence —
HIGH
1 sources
95.0%
(W 25%)
DATA
7 years (CR2016)
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Legibility and Illumination
Ease of reading time in various lighting conditions.
Ideal: High-contrast dial with luminous markers or backlight functional in low light.
Confidence —
HIGH
3 sources
60.0%
(W 20%)
PRO
Simple, high-contrast LCD is easy to read at a glance in normal light.Includes an LED "micro-light" for darkness.
CON
Backlight is dim and illuminates from one side, limiting nighttime legibility.
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Magnetic and Shock Resistance
Ability to maintain accuracy under physical or magnetic stress.
Ideal: Antimagnetic protection ≥4800 A/m and compliance with ISO 1413 shock standards.
Confidence —
MEDIUM
1 sources
0.0%
(W 20%)
DATA
—
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See details on our Scoring Method.
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| Created | 2025-10-27 | COMPLETE |
| Updated | 2025-10-30 | COMPLETE |
| Published | — | PUBLISHED |
| Scored | 2025-10-27 | COMPLETE |
| 2025-10-30 | UPDATED |
| 2025-10-27 | UPDATED |
| 2025-10-27 | UPDATED |
| 2025-10-27 | UPDATED |
| 2025-10-27 | UPDATED |
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