Hamilton Khaki Aviation Pilot Auto vs Seiko Presage SSA425 Open Heart
Hamilton's pilot watch meets Seiko's timepiece
Quick Verdict
The Seiko Presage SSA425 Open Heart ($250–$500) delivers Seiko In-House Automatic technology in the tier below the Hamilton Khaki Aviation Pilot Auto ($1,000–$1,500). The Presage SSA425 Open Heart measures 40.5mm and is rated 50m (5 ATM). The Khaki Aviation Pilot Auto justifies its premium with Swiss Made heritage and Automatic H-10 (ETA 2824-2 base). Both represent excellent choices in the luxury watch category.
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Specifications Compared
| Feature | Hamilton Khaki Aviation Pilot Auto | Seiko Presage SSA425 Open Heart |
|---|---|---|
| Price | $1,000–$1,500 | $250–$500 |
| Case Size | 38mm | 40.5mm |
| Movement | Automatic H-10 (ETA 2824-2 base) | Automatic Caliber 4R38 |
| Caliber Type | Hamilton/ETA Automatic | Seiko In-House Automatic |
| Power Reserve | 80 Hours | 41 Hours |
| Water Resistance | 100m (10 ATM) | 50m (5 ATM) |
| Crystal | Sapphire Crystal | Hardlex Crystal |
| Case Material | Stainless Steel | Stainless Steel |
| Origin | Swiss Made | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Hamilton's design language vs Seiko's approach
The Hamilton Khaki Aviation Pilot Auto features a Stainless Steel case at 38mm with Sapphire Crystal protection. The Seiko Presage SSA425 Open Heart offers Stainless Steel construction at 40.5mm with Hardlex Crystal. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Automatic H-10 (ETA 2824-2 base) vs Automatic Caliber 4R38
The Khaki Aviation Pilot Auto runs the Automatic H-10 (ETA 2824-2 base) (Hamilton/ETA Automatic, 80 Hours power reserve) at 21,600 vph (3 Hz) frequency. The Presage SSA425 Open Heart uses the Automatic Caliber 4R38 (Seiko In-House Automatic, 41 Hours reserve) at 21,600 vph (3 Hz). The Khaki Aviation Pilot Auto edges ahead on power reserve.
Wearability & Fit
38mm vs 40.5mm — different wrist presence
At 38mm, the Khaki Aviation Pilot Auto wears more compactly on smaller wrists compared to the Presage SSA425 Open Heart at 40.5mm. Water resistance differs: 100m (10 ATM) vs 50m (5 ATM).
Value & Cost of Ownership
Seiko sits in the lower tier
The Hamilton Khaki Aviation Pilot Auto sits at $1,000–$1,500 and the Seiko Presage SSA425 Open Heart at $250–$500. On the specs that outlast any price: the Khaki Aviation Pilot Auto uses Sapphire Crystal with 80 Hours, against Hardlex Crystal and 41 Hours on the Presage SSA425 Open Heart. Service intervals are typically 5-7 years for both.
Water Resistance
100m (10 ATM) vs 50m (5 ATM)
The Khaki Aviation Pilot Auto is rated to 100m (10 ATM) while the Presage SSA425 Open Heart handles 50m (5 ATM). The Khaki Aviation Pilot Auto is better suited for water activities.
Our Verdict
Hamilton
Khaki Aviation Pilot Auto
Choose the Hamilton Khaki Aviation Pilot Auto if you prioritize Hamilton/ETA Automatic engineering, Swiss Made craftsmanship, and 100m (10 ATM) water resistance. At $1,000–$1,500, it delivers Automatic H-10 (ETA 2824-2 base) with 80 Hours power reserve.
Check Price on AmazonSeiko
Presage SSA425 Open Heart
Choose the Seiko Presage SSA425 Open Heart if you value Seiko In-House Automatic technology, Made in Japan heritage, and 40.5mm proportions. At $250–$500, the Automatic Caliber 4R38 with 41 Hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Hamilton Khaki Aviation Pilot Auto and Seiko Presage SSA425 Open Heart represent two distinct approaches to fine watchmaking — the Hamilton bringing Swiss Made tradition while Seiko delivers Made in Japan engineering.
Frequently Asked Questions
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How This Page Was Made
Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.