⌚ Seagull ST3600 Mechanical Movement – Precision Hand-Wound ST36 Caliber for ETA 6497 Watch Cases

📝 1. Description

The Seagull ST3600 mechanical movement is a high-precision, hand-wound caliber that offers reliability, craftsmanship, and classic horological appeal. Modeled after the iconic ETA 6497 movement, the ST3600 (also known as ST36) is a robust and time-tested Chinese-made alternative that powers countless open-heart, skeleton, and classic manual watches. With its 17-jewel construction, durable metal gears, and large, easy-to-service layout, it is a favorite among professional watchmakers, enthusiasts, and modders.

Manufactured by Tianjin Seagull Watch Group, one of the world’s largest mechanical movement producers, the ST3600 is a trusted replacement movement that fits cases originally built for ETA 6497/6498 types. This movement offers a smooth 21,600 VPH beat rate, high torque for larger hands, and a generous power reserve of up to 48 hours. It has a large, highly visible balance wheel, making it particularly attractive in watches with exhibition case backs or open-heart dials.

Whether you're repairing a vintage timepiece, assembling a custom build, or exploring watchmaking as a craft, the ST3600 delivers a blend of precision, affordability, and heritage-inspired mechanical design that makes it one of the most respected hand-wind calibers available today.

📌 2. Key Points

• 🧭 Manual Hand-Wind Mechanical Movement
  Requires manual winding for power — no rotor or automatic winding.
  
• ⛓️ 17 Jewels Construction
  Ensures long-lasting durability and smooth gear engagement.
  
• 🕒 Hours, Minutes, and Sub-Seconds Layout
  Sub-seconds hand positioned at 6 o'clock.
  
• 🌀 ETA 6497 Clone Compatibility
  Direct replacement for ETA 6497-based cases and movements.
  
• 🔁 High Torque Output
  Supports larger hands and thicker dial designs.
  
• ⚙️ Robust and Serviceable Design
  Large parts and simple construction ideal for training and maintenance.
  
• 🕰️ 48-Hour Power Reserve
  Long-lasting energy from a single full wind.
  
• 🎯 Accurate 21,600 BPH Beat Rate
  Smooth ticking with excellent timekeeping precision.
  
• 🔩 Standard 16.5 Ligne (36.6mm Diameter)
  Common sizing for pilot, pocket, and vintage-style wristwatches.
  
• 🛠️ Perfect for Modding and Custom Builds
  Favored by enthusiasts and watch microbrands for design flexibility.
  

🌟 3. Benefits

🔧 Ideal for Watch Repair and Assembly

The ST3600 is perfect for replacing worn-out ETA 6497/6498 calibers. Its similar layout and specs make it a plug-and-play replacement for many Swiss and Chinese hand-wound watch cases.

🏗️ Easy to Work With

With a large movement size (36.6mm) and spacious layout, the ST3600 is ideal for beginners learning mechanical watch repair, as well as seasoned professionals looking for dependable quality.

🔄 Reliable and Smooth Performance

Its 21,600 vibrations per hour ensure steady, accurate movement of the hands, while the 17-jewel gear train keeps friction low and performance high.

👓 Showcase-Ready Design

The movement features a visually appealing open balance wheel and gear train, making it an excellent choice for skeleton watches and timepieces with exhibition case backs.

💪 Rugged and Long-Lasting

The sturdy metal components, jewel-supported gears, and well-balanced design provide a movement that can last for decades with proper maintenance.

💼 Microbrand Friendly

The ST3600 is widely used in affordable and mid-range mechanical watches manufactured by both mainstream and boutique brands. It offers mechanical credibility at scale.

💡 Low-Cost Alternative to Swiss Movements

For those seeking ETA-level quality without the Swiss price tag, the ST3600 provides a high-performance solution at a wholesale-friendly cost.

🔄 Flexibility in Modding

Enthusiasts love the ST3600 for its compatibility with a variety of dial, case, and hand designs, offering endless creative opportunities for DIY watch builds.

🔋 Extended Power Reserve

With up to 48 hours of runtime on a full wind, users can enjoy convenience without needing daily winding.

🧪 Quality Assurance from Seagull

Produced by Tianjin Seagull, a respected brand in global watchmaking, the movement benefits from quality-controlled manufacturing and consistent performance.

💡 4. Why You Choose This

✅ Built by One of the World’s Largest Movement Makers

Seagull has a decades-long legacy of engineering precise and reliable mechanical watch movements. The ST3600 reflects this legacy with consistency and trust.

✅ Timeless Hand-Winding Appeal

In a world full of quartz and automatic watches, hand-wound movements provide a unique and romantic horological experience. Winding the crown daily connects the wearer to the heart of the watch.

✅ Budget-Friendly with Professional Specs

You get ETA-like reliability, a sapphire-jewel bearing system, and decent precision for a fraction of the price of Swiss calibers.

✅ Readily Available Parts and Support

ST3600-compatible components — dials, hands, stems, and screws — are widely available, ensuring that repairs and customizations are never a hassle.

✅ Training & Educational Use

Many watchmaking schools and online courses use this caliber for hands-on learning due to its large size, straightforward construction, and resilience.

✅ Ideal for Watch Customizers

The ST3600 supports everything from simple retro designs to fully custom, artistic builds with hand-painted dials, unique handsets, or open-skeleton architecture.

✅ Compatibility with Popular Case Sizes

Its 36.6mm diameter makes it perfect for pilot watches, dress watches, and vintage recreations, especially when fitted into 44–47mm cases.

✅ Upgrade Potential

With minor modifications, the movement can be decorated, upgraded with blued screws, or given Côtes de Genève finishes for a luxury touch.

✅ Proven in the Field

Tens of thousands of watches use this movement worldwide. It is field-tested and known to perform well in daily wear scenarios.

✅ Clean Power and Winding Feel

The tactile satisfaction of manually winding this movement offers a more engaging and satisfying experience than most quartz or automatic systems.

✅ 5. Conclusion

The Seagull ST3600 (ST36) Mechanical Movement is a cornerstone of modern affordable horology. Its heritage-based architecture, modeled after the Swiss ETA 6497, delivers classic mechanical charm, reliable performance, and impressive modding potential. Whether you're designing your first watch, repairing an existing one, or learning the art of horology, the ST3600 is a versatile, high-quality, and budget-conscious choice.

With features like 17 jewels, a sub-second dial, hand-winding operation, and a 48-hour power reserve, it gives you everything you’d expect from a premium mechanical movement — minus the price tag. Trusted by thousands of microbrands and independent watchmakers, it continues to bridge the gap between quality and affordability in a timeless way.

If you're looking for performance, compatibility, and customization in a mechanical movement, the ST3600 is ready to meet every horological challenge with grace.