Seiko - Grand Seiko Hi-Beat 36000 - 4520-7010 - Men - 1970

Now available at auction from Second Vintage The Grand Seiko 45GS series represents a pinnacle of Japanese watchmaking from the golden era of mechanical timepieces. Born in the Daini Seikosha factory, the caliber 4520A is celebrated by collectors for its true hi-beat 36,000 vibrations per hour escapement, delivering exceptional accuracy and a mesmerizingly smooth sweep of the seconds hand. Encased in a design that perfectly executes Taro Tanaka’s famous Grammar of Design, this reference 4520-7010 features broad, flat surfaces and sharp angles that play brilliantly with light. Preserved with a distinct, character-rich patina, this manual-wind Grand Seiko is a testament to an era when Seiko set out to conquer the strict chronometer standards of the Swiss watch industry. Brand: Seiko Model: Grand Seiko Hi-Beat 36000 Reference Number: 4520-7010 Serial Number: 040464 Movement: Manual wind, caliber 4520A, 25 jewels Dial: Silver sunburst with applied indices, exhibiting stardust patina and edge spotting Case Size: 36 mm (excluding the crown) Case Material: Stainless steel Production Year: 1970 Condition: Good vintage condition with honest wear and attractive dial aging Dial and Hands The silver sunburst dial features a striking layout defined by applied faceted baton indices with black central inserts, matching the sharp dauphine hands to provide excellent legibility. The dial displays the applied Seiko and GS logos, with the printed Hi-Beat 36000 text and the Daini factory lightning bolt emblem positioned above six o'clock. A thorough visual inspection reveals clear signs of age and character. The surface has developed an even, speckled stardust patina throughout. Additionally, there is localized darker spotting and moisture-related staining along the outer periphery of the dial, most noticeably between the six and nine o'clock positions. The hands remain well-preserved, showing only minor age-consistent oxidation upon close magnification. Case and Crystal The 36 mm stainless steel case is a classic execution of the Grammar of Design, featuring a cushion-like tonneau profile with brushed upper surfaces and polished flanks. The case remains in good vintage condition, presenting honest signs of daily wear, including surface scratches, minor scuffs, and slightly softened lug profiles consistent with normal use and historical handling. The watch retains its original GS-signed crown, which features crisp ridging. Turning the watch over, the solid stainless steel caseback is proudly adorned with the iconic gold Seiko GS medallion. The medallion is fully intact, though it displays light surface scuffs. The caseback engravings, including the reference 4520-7010 and serial number 040464, remain fully legible. The watch is fitted with its original-style acrylic crystal, which is clear, showing minimal signs of wear and allowing an unobstructed view of the dial's character. Movement Powering this timepiece is the legendary Daini Seikosha caliber 4520A, a 25-jewel manual-wind movement operating at a high-beat rate of 36,000 vibrations per hour. The movement is beautifully finished and clearly stamped with the caliber designation and the movement serial number 106362. Performing well within expected vintage tolerances; running strong and steady. The timegrapher results show a deviation of +20 to +22 seconds per day. Strap The watch is fitted with a black leather strap featuring prominent white contrast stitching, complementing the vintage aesthetic of the timepiece. It is secured by a standard stainless steel pin buckle. Condition This Grand Seiko is presented in good vintage condition. It is a piece that has been worn and enjoyed, which is reflected in the honest surface wear on the case and the distinctive stardust patina and edge spotting on the dial. The structural integrity of the case remains sound, and the gold caseback medallion is wonderfully preserved. Dimensions Case Size: 36 mm (excluding the crown) Remarks For the dedicated vintage Seiko collector, the 45GS holds a mandatory place in the watch box. The combination of the hand-wound 36,000 bph movement and the iconic case geometry makes it one of the most historically significant watches to emerge from Japan. The unique dial aging on this specific example gives it an unmistakable vintage charm, distinguishing it from pristine, unworn safe queens and offering a watch with genuine soul and history. History Introduced in 1968, the 45GS series was Daini Seikosha’s answer to the high-beat automatic movements produced by their internal rival, Suwa Seikosha. By utilizing a manual-wind architecture, Daini was able to create a thinner, more elegant movement that still housed the robust 36,000 bph escapement necessary for chronometer-level precision. The 4520 caliber quickly became legendary, not only for its technical prowess but also for being the foundation of the Astronomical Observatory Chronometers that stunned the Swiss watchmaking establishment. Today, these high-beat manual Grand Seikos are revered as some of the finest mechanical watches ever produced in Japan. / Second Vintage SKU: SEI-SGX-0002