{"product_id":"seiko-7431-5360-acier-cadran-noir-geometrique-1985","title":"Vintage Seiko Watch 7431-5360 — Black Geometric Dial (1985)","description":"\u003cdiv style=\"margin: 28px 0; padding: 22px 12px; border-bottom: 1px solid #e2ddd5; text-align: center;\"\u003e\n\u003cp style=\"margin: 0 0 10px; font-size: 11px; letter-spacing: 0.18em; text-transform: uppercase; opacity: 0.5;\"\u003eAtelier Note\u003c\/p\u003e\n\u003cp style=\"margin: 0; font-style: italic; font-size: 16px; line-height: 1.7;\"\u003eAgainst the black lacquer, an aqua-green line draws two nested rectangles and connects their corners: a dial decoration owing nothing to light, everything to design. It is 1985.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch2\u003eA steel rectangle and a black dial with a geometric motif\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003ewatch Seiko\u003c\/strong\u003e is a \u003cstrong\u003erectangular quartz\u003c\/strong\u003e watch in \u003cstrong\u003esteel\u003c\/strong\u003e, reference \u003cstrong\u003e7431-5360\u003c\/strong\u003e, produced in \u003cstrong\u003e1985\u003c\/strong\u003e. The case is a rectangle with \u003cstrong\u003ecut corners\u003c\/strong\u003e, fully polished, whose upper and lower facets taper into the bracelet with no visible break. From the front, the watch shows only a steel plate and a black opening.\u003c\/p\u003e\n\u003cp\u003eThe \u003cstrong\u003eblack lacquered dial\u003c\/strong\u003e bears a printed motif in an \u003cstrong\u003eaqua-green line\u003c\/strong\u003e: a first rectangle runs along the edge, a second closes at the centre, and four diagonals connect their corners. The effect is that of a perspective drawing rendered flat. Only four \u003cstrong\u003eapplied baton markers\u003c\/strong\u003e mark twelve, three, six and nine o'clock; the rest of the dial bears only the \u003cem\u003eSEIKO QUARTZ\u003c\/em\u003e signature.\u003c\/p\u003e\n\u003cp\u003eThe \u003cstrong\u003eoriginal steel bracelet\u003c\/strong\u003e is \u003cstrong\u003eintegrated into the case\u003c\/strong\u003e, with wide flat links separated by fine grooves, alternating brushed and polished surfaces. It closes at approximately 21cm and extends the line of the case to the Buckle.\u003c\/p\u003e\n\u003cp\u003eThe movement is a \u003cstrong\u003eSeiko 7431 calibre\u003c\/strong\u003e, an \u003cstrong\u003eanalogue quartz\u003c\/strong\u003e movement with two jewels, beating at 32,768 Hz for a stated accuracy of around fifteen seconds per month, with an \u003cstrong\u003eend-of-battery indicator\u003c\/strong\u003e. It has been checked by our watchmakers, the battery is new, and it carries a 1-year guarantee.\u003c\/p\u003e\n\u003ch3 style=\"margin: 40px 0 16px;\"\u003eThree points to note\u003c\/h3\u003e\n\u003cdiv style=\"margin: 20px 0; padding-left: 16px; border-left: 1px solid #e2ddd5;\"\u003e\n\u003cp style=\"margin: 0 0 4px; font-size: 12px; letter-spacing: 0.1em; opacity: 0.45;\"\u003e01\u003c\/p\u003e\n\u003cp style=\"margin: 0 0 18px;\"\u003e\u003cstrong\u003eBlack dial with printed geometric motif\u003c\/strong\u003e — two nested rectangles connected by four diagonals, in an aqua-green line.\u003c\/p\u003e\n\u003cp style=\"margin: 0 0 4px; font-size: 12px; letter-spacing: 0.1em; opacity: 0.45;\"\u003e02\u003c\/p\u003e\n\u003cp style=\"margin: 0 0 18px;\"\u003e\u003cstrong\u003eOriginal integrated steel bracelet\u003c\/strong\u003e — grooved flat links, in the exact continuation of the case.\u003c\/p\u003e\n\u003cp style=\"margin: 0 0 4px; font-size: 12px; letter-spacing: 0.1em; opacity: 0.45;\"\u003e03\u003c\/p\u003e\n\u003cp style=\"margin: 0;\"\u003e\u003cstrong\u003eHands marked by time\u003c\/strong\u003e — the hour and minute hands have lost part of their finish, detailed in the Overall condition bullet point.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch3 style=\"margin: 40px 0 16px;\"\u003eWhy choose this Seiko from 1985?\u003c\/h3\u003e\n\u003cp\u003eThis \u003cstrong\u003epre-owned Seiko watch\u003c\/strong\u003e occupies a precise place among our \u003cstrong\u003eJapanese vintage watches\u003c\/strong\u003e: it is a Japanese dress watch from the mid-1980s, the kind that Seiko produced in thousands of never-named references, and whose design lies entirely in the dial. This one has kept its original steel bracelet, which has become rare on these cases with integrated lugs, impossible to replace with a standard bracelet.\u003c\/p\u003e \n\u003cp\u003eLike all our \u003cstrong\u003epre-owned luxury watches\u003c\/strong\u003e, this one has been opened and checked by our partner watchmakers: movement verification, examination of the dial, hands and case. Every \u003cstrong\u003eSeiko vintage watch\u003c\/strong\u003e we offer comes with an Atelier Victor invoice serving as a certificate, a 1-year guarantee and lifetime-guaranteed authenticity.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003e→ \u003ca href=\"\/en\/collections\/montres-seiko-vintage\" title=\"Vintage Seiko Watches\"\u003eDiscover our vintage Seiko watches\u003c\/a\u003e\u003cbr\u003e→ \u003ca href=\"\/en\/collections\/montres-vintage-japonaises\" title=\"Vintage Japanese Watches\"\u003eSee our selection of Japanese watches\u003c\/a\u003e\u003c\/em\u003e\u003c\/p\u003e\n\u003ch3 style=\"margin: 40px 0 16px;\"\u003eTechnical specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Seiko\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel:\u003c\/strong\u003e Rectangular quartz, black dial\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReference:\u003c\/strong\u003e 7431-5360\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eYear:\u003c\/strong\u003e 1985\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSerial number:\u003c\/strong\u003e 510•••\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrigin:\u003c\/strong\u003e Japan\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGender:\u003c\/strong\u003e Men's watch, women's watch (Unisex)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMovement:\u003c\/strong\u003e Analogue quartz, Seiko calibre 7431, 2 jewels\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunctions:\u003c\/strong\u003e Hours, minutes, seconds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCase:\u003c\/strong\u003e Polished steel, rectangular shape with cut corners\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCase back:\u003c\/strong\u003e Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 25mm (26.3mm with the crown)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLug-to-lug:\u003c\/strong\u003e 32mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThickness:\u003c\/strong\u003e 6.35mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLug width:\u003c\/strong\u003e 18mm (integrated lugs)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCrown:\u003c\/strong\u003e Steel, original\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDial:\u003c\/strong\u003e Black lacquered, printed geometric motif, applied baton markers, dial code 7431-5490\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHands:\u003c\/strong\u003e Steel batons, original\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCrystal:\u003c\/strong\u003e Mineral\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBracelet:\u003c\/strong\u003e Steel with integrated lugs, approximately 21cm, original\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuckle:\u003c\/strong\u003e Steel, original\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eService:\u003c\/strong\u003e [to be completed]\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin: 40px 0 16px;\"\u003eCondition and guarantee\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall condition:\u003c\/strong\u003e Good state of preservation. The black dial is clean, the printed motif and applied markers are intact. The hour and minute hands have lost part of their finish along their entire length, which is visible up close and in our photographs; the centre seconds hand is clean. The polished case and bracelet show surface scratches from wear on their surfaces, notably on the sides. Mineral Crystal in good condition (9\/10).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater resistance:\u003c\/strong\u003e Not guaranteed (vintage watch)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAuthenticity:\u003c\/strong\u003e Lifetime guarantee\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanics:\u003c\/strong\u003e Checked and functional quartz movement, new battery, 1-year guarantee\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded:\u003c\/strong\u003e Atelier Victor invoice serving as a certificate, protective case\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot included:\u003c\/strong\u003e Original box and papers\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin: 40px 0 16px;\"\u003eFrequently asked questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat movement powers this Seiko?\u003c\/strong\u003e \u003cbr\u003eA Seiko 7431 calibre, analogue quartz with two jewels, developed by the Daini Seikosha division. It vibrates at 32,768 Hz for a stated accuracy of around fifteen seconds per month, runs on an SR721SW battery and includes an end-of-life indicator: the seconds hand begins advancing in two-second jumps when it needs to be changed. It displays the hours, minutes and seconds, with no date.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat does the code printed at the bottom of the dial mean?\u003c\/strong\u003e\u003cbr\u003eThe marking \u003cem\u003eJAPAN 7431-5490 R\u003c\/em\u003e combines the movement calibre, here 7431, with the dial code, here 5490. It is an identification marking specific to Seiko. The case reference, meanwhile, is engraved on the caseback: it is the one that identifies the model, and it is the one we list in the specifications.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan the bracelet be adjusted to my size?\u003c\/strong\u003e\u003cbr\u003eIt fastens at about 21cm as it is, which leaves room on most wrists. Links can be removed by a watchmaker. As the attachments are integrated into the case, a standard bracelet cannot be fitted in its place: the original bracelet is part of the watch's design.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes a quartz watch of this age need servicing?\u003c\/strong\u003e\u003cbr\u003eVery little, and that is its whole point. The battery is changed every two to three years by a watchmaker, who will also check the gaskets. There is no periodic service as on a mechanical watch. The main point of attention is not to leave a depleted battery in the case, as a leaking battery can reach the movement.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this piece suitable for a slim or large wrist?\u003c\/strong\u003e\u003cbr\u003eAt 25mm wide, 32mm lug-to-lug and 6.35mm thick, it suits wrists of around 15 to 19cm — a guide, never a rule: everyone wears what they like. A rectangular case extended by an integrated bracelet has more visual presence than its dimensions might suggest.\u003c\/p\u003e\n \u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Quel mouvement équipe cette Seiko ?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Un calibre Seiko 7431, quartz analogique à deux rubis, développé par la division Daini Seikosha. Il oscille à 32 768 Hz pour une précision annoncée de l'ordre de quinze secondes par mois, fonctionne sur une pile SR721SW et intègre un indicateur de fin de pile : la trotteuse se met à avancer par sauts de deux secondes lorsqu'il faut la changer. Il affiche les heures, les minutes et les secondes, sans date.\"}}, {\"@type\": \"Question\", \"name\": \"Que signifie le code imprimé au bas du cadran ?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"La mention JAPAN 7431-5490 R associe le calibre du mouvement, ici 7431, au code du cadran, ici 5490. C'est une indication d'atelier propre à Seiko. La référence du boîtier, elle, est gravée au fond de boîte : c'est elle qui identifie le modèle, et c'est celle que nous indiquons dans les caractéristiques.\"}}, {\"@type\": \"Question\", \"name\": \"Le bracelet peut-il être mis à ma taille ?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Il ferme sur environ 21cm en l'état, ce qui laisse de la marge sur la plupart des poignets. Le retrait de maillons se fait chez un horloger. Les attaches étant intégrées au boîtier, un bracelet standard ne peut pas être monté à la place : le bracelet d'origine fait partie du dessin de la montre.\"}}, {\"@type\": \"Question\", \"name\": \"Faut-il entretenir une montre à quartz de cet âge ?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Peu, et c'est tout son intérêt. La pile se change tous les deux à trois ans chez un horloger, qui en profite pour vérifier les joints. Il n'y a pas de révision périodique comme sur une mécanique. Le point de vigilance est de ne pas laisser une pile usée dans le boîtier, une pile qui coule pouvant atteindre le mouvement.\"}}, {\"@type\": \"Question\", \"name\": \"Cette pièce convient-elle à un poignet fin ou large ?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Avec 25mm de large, 32mm de corne à corne et 6,35mm d'épaisseur, elle se place sur des poignets de 15 à 19cm environ — un repère, jamais une règle : chacun porte ce qui lui plaît. Un boîtier rectangulaire prolongé par un bracelet intégré occupe visuellement plus que ses cotes ne le laissent penser.\"}}]}\n\u003c\/script\u003e  ","brand":"Seiko","offers":[{"title":"Default Title","offer_id":54727445381457,"sku":"510839 7431-5360","price":409.5,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0703\/8576\/2597\/files\/montre-seiko-7431-5360-acier-cadran-noir-geometrique-1985-atelier-victor-10.jpg?v=1789534495","url":"https:\/\/ateliervictor.co\/en\/products\/vintage-seiko-7431-5360-watch-geometric-black-dial-1985","provider":"Atelier Victor","version":"1.0","type":"link"}