{"product_id":"sw-j-frame-model-640-3-internal-parts-set-used","title":"Smith \u0026 Wesson J Frame Model 640-3 Internal Parts Set - Used","description":"\u003cp\u003e\u003cstrong\u003eThis listing is for a used Smith \u0026amp; Wesson J Frame Model 640-3 internal parts set. Factory OEM parts sold as-is.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eKeep your Model 640-3 Centennial running smoothly with this genuine Smith \u0026amp; Wesson factory internal parts lot. The Model 640-3 is the stainless steel, fully shrouded hammer (DAO) Centennial J Frame chambered in .38 Special — a popular choice for concealed carry and backup duty use. This set covers key action springs and components for gunsmiths performing action work or spring replacement on this classic carry revolver.\u003c\/p\u003e\n\n\u003ch2\u003ePart Details\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e JS1391\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e Used\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eParts Included:\u003c\/strong\u003e\n  \u003cul\u003e\n    \u003cli\u003eMainspring (1)\u003c\/li\u003e\n    \u003cli\u003eBolt Spring \u0026amp; Plunger (1 set)\u003c\/li\u003e\n    \u003cli\u003ePin (1)\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e Smith \u0026amp; Wesson J Frame Model 640-3\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCaliber:\u003c\/strong\u003e .38 Special\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFrame:\u003c\/strong\u003e J Frame (Stainless Steel)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStyle:\u003c\/strong\u003e Centennial (fully shrouded hammer, DAO)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM:\u003c\/strong\u003e Smith \u0026amp; Wesson Factory Part\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eModel Compatibility\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eFrame\u003c\/th\u003e\n\u003cth\u003eCaliber\u003c\/th\u003e\n\u003cth\u003eCompatible\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 640-3\u003c\/td\u003e\n\u003ctd\u003eJ Frame (Stainless)\u003c\/td\u003e\n\u003ctd\u003e.38 Special\u003c\/td\u003e\n\u003ctd\u003e✅ Yes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 640 (other dash)\u003c\/td\u003e\n\u003ctd\u003eJ Frame (Stainless)\u003c\/td\u003e\n\u003ctd\u003e.38 Spl \/ .357 Mag\u003c\/td\u003e\n\u003ctd\u003e⚠️ Verify dash number\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 442\u003c\/td\u003e\n\u003ctd\u003eJ Frame (Aluminum)\u003c\/td\u003e\n\u003ctd\u003e.38 Special+P\u003c\/td\u003e\n\u003ctd\u003e⚠️ Verify fitment — similar Centennial\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 642\u003c\/td\u003e\n\u003ctd\u003eJ Frame (Aluminum)\u003c\/td\u003e\n\u003ctd\u003e.38 Special+P\u003c\/td\u003e\n\u003ctd\u003e⚠️ Verify fitment — similar Centennial\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 36 \/ 60\u003c\/td\u003e\n\u003ctd\u003eJ Frame (Steel)\u003c\/td\u003e\n\u003ctd\u003e.38 Spl \/ .357 Mag\u003c\/td\u003e\n\u003ctd\u003e❌ No — exposed hammer models differ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 342 AirLite\u003c\/td\u003e\n\u003ctd\u003eJ Frame (Aluminum)\u003c\/td\u003e\n\u003ctd\u003e.38 Special+P\u003c\/td\u003e\n\u003ctd\u003e❌ No — different frame material\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cp\u003e\u003cem\u003eNote: Spring dimensions and pin fitment can vary between Model 640 dash numbers due to engineering changes. Always confirm your exact model and dash number before ordering. To find your model number, swing out the cylinder and check behind the yoke on the frame.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eDisassembly and reassembly by a qualified gunsmith is required. Some parts may require fitting. Verify correct action function after installation. Factory replacement parts are manufactured to the same specifications, tolerances, and materials as the originals.\u003c\/p\u003e\n\n\u003cp\u003eQuestions? Shoot us an email or give us a call — we're here for all your S\u0026amp;W needs.\u003c\/p\u003e","brand":"Smith \u0026 Wesson","offers":[{"title":"Default Title","offer_id":39445744418874,"sku":"JS1391","price":19.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1423\/2020\/products\/DSC00261_72ba8d6d-a03b-444f-b9d9-28b6b7ebb0be.jpg?v=1786111923","url":"https:\/\/usagunsandgear.com\/products\/sw-j-frame-model-640-3-internal-parts-set-used","provider":"USA Guns And Gear","version":"1.0","type":"link"}