Seiko Actus SS 6106-8670 (1974)

Now available at auction from Second Vintage This 1974 Seiko Actus SS stands out through its exceptionally clean and vibrant blue sunburst dial and a fascinating layer of documented provenance. The caseback bears a unique commemorative engraving celebrating 25 years of service at NGK Spark Plug Co., Ltd. in April 1975, elevating this sought-after Japanese Domestic Market timepiece with distinct corporate history. Brand: Seiko Model: Actus SS Reference Number: 6106-8670 Serial Number: 491537 Movement: Automatic, caliber 6106C, 23 jewels Dial: Vibrant blue sunburst with applied silver-tone indices and day-date window Case Size: 37 mm (excluding the crown) Case Material: Stainless steel Production Year: 1974 Condition: Good vintage condition. Timegrapher: -17s-20s/day, performing remarkably well. Dial and Hands The dial is exceptionally clean and vibrant, showcasing a striking blue sunburst finish. Applied silver-tone indices feature black central stripes that perfectly match the baton hands. Applied Seiko and 5 Actus logos sit proudly on the dial, alongside a clean day-date window positioned at 3 o'clock. The hands display clean surfaces with minimal signs of oxidation, while the luminous material remains intact with a touch of slight aging. There is no visible moisture damage, spotting, or significant degradation. Case and Crystal The stainless steel C-shape case retains its original geometry, presenting brushed top surfaces that transition seamlessly into polished flanks. It displays honest vintage wear, with moderate surface scratches and minor dings consistent with age and normal use. A polished smooth bezel ring is integrated into the case, showing light surface scratches matching the rest of the watch. The caseback carries the distinctive NGK Spark Plug presentation engraving. A recessed crown is positioned at 4 o'clock, displaying a knurled edge. The flat crystal is clear, free of major scratches, chips, or crazing, providing an unobstructed view of the vibrant dial beneath. Movement Powering the watch is the automatic Seiko caliber 6106C, featuring 23 jewels and a visible rotor. The plates and bridges present a generally clean appearance with no severe corrosion or damage visible, though some minor dirt and residue can be seen around the outer case sealing edge. The movement is properly signed with SEIKO, 23 JEWELS, 6106C, and JAPAN. Recording -17s-20s/day on the timegrapher, it is exhibiting remarkable accuracy and consistency, performing brilliantly for a vintage timepiece. Strap The watch is fitted with a black leather strap featuring alligator-style embossing and white contrast stitching. It is an attractive modern strap that shows light wear and creasing from use. Condition Good vintage condition. The case exhibits honest vintage wear with moderate surface scratches and minor dings, while preserving its classic 1970s C-shape geometry. The dial and hands are exceptionally well-preserved and vibrant. The movement is generally clean with only minor residue near the outer sealing edge, and supported by the recorded timegrapher result, is performing very strongly. Dimensions 37 mm (excluding the crown) Remarks This Actus SS offers a compelling combination of a striking blue sunburst dial and a robust 6106C automatic movement. The unique NGK Spark Plug corporate engraving provides a documented connection to mid-century Japanese industrial history, making it a highly appealing acquisition for the vintage enthusiast. History The Seiko 5 Actus line was produced primarily for the Japanese Domestic Market, designed specifically to appeal to young professionals of the era. The "SS" designation on the dial stands for "Second Setting," indicating that the movement features a hacking seconds function for precise time synchronization. This model utilizes the 23-jewel Seiko caliber 6106C, an automatic movement operating at 21,600 vibrations per hour and featuring a push-style quickset mechanism for adjusting both the day and date displays. / Second Vintage SKU: SEI-SAS-0002