{"id":4626,"date":"2026-05-22T09:18:16","date_gmt":"2026-05-22T09:18:16","guid":{"rendered":"https:\/\/haomaerprecision.com\/?p=4626"},"modified":"2026-05-22T09:19:08","modified_gmt":"2026-05-22T09:19:08","slug":"cnc-machining-comparison-of-304-316-and-18-8-stainless-steel","status":"publish","type":"post","link":"https:\/\/haomaerprecision.com\/zh\/cnc-machining-comparison-of-304-316-and-18-8-stainless-steel\/","title":{"rendered":"CNC Machining Comparison of 304, 316 and 18-8 Stainless Steel"},"content":{"rendered":"
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Introduction<\/h2>\r\n

When selecting stainless steel for CNC machined parts, the most common confusion is between 304 stainless steel, 316 stainless steel, and 18-8 stainless steel<\/strong>. Engineers and buyers often mix up these grades, which directly impacts corrosion resistance, machining difficulty, part quality, and cost<\/strong>.<\/p>\r\n

This guide breaks down 18-8 vs 304 vs 316 stainless steel differences<\/strong>, compares their chemical composition, mechanical properties, CNC machinability, and typical applications<\/strong>, and helps you choose the best stainless steel grade for your CNC projects<\/strong>\u2014whether for medical devices, marine parts, food equipment, or industrial machinery.<\/p>\r\n\r\n

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What Is 18-8 Stainless Steel?<\/h2>\r\n

18-8 stainless steel<\/strong> is a widely used industry term for austenitic stainless steel with approximately 18% chromium and 8% nickel<\/strong>. It is not an official grade<\/strong> but a common reference.<\/p>\r\n

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  • 18% Chromium<\/strong>: Provides basic corrosion resistance<\/li>\r\n
  • 8% Nickel<\/strong>: Stabilizes austenitic structure, improves toughness<\/li>\r\n
  • Equivalent to 304<\/strong>: In most cases, 18-8 = 304 stainless steel<\/strong><\/li>\r\n<\/ul>\r\n\r\n
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    304 Stainless Steel: The Most Popular CNC Grade<\/h2>\r\n

    304 stainless steel<\/strong> (also known as 18-8 stainless steel, A2 stainless steel<\/strong>) is the most common, versatile, and cost-effective austenitic stainless steel<\/strong> for CNC machining.<\/p>\r\n\r\n

    Chemical Composition<\/h3>\r\n
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    • Chromium: 18\u201320%<\/li>\r\n
    • Nickel: 8\u201311%<\/li>\r\n
    • No Molybdenum<\/li>\r\n<\/ul>\r\n\r\n

      Key Benefits<\/h3>\r\n
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      • \u2705 Excellent general corrosion resistance<\/li>\r\n
      • \u2705 Easy CNC machining<\/li>\r\n
      • \u2705 Cost-effective<\/li>\r\n
      • \u2705 Good strength & toughness<\/li>\r\n
      • \u2705 Food-safe, non-magnetic<\/li>\r\n<\/ul>\r\n\r\n

        Common Applications<\/h3>\r\n
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        • Food processing equipment<\/li>\r\n
        • Kitchen appliances<\/li>\r\n
        • Medical housings<\/li>\r\n
        • General machinery parts<\/li>\r\n
        • Brackets, fasteners, covers<\/li>\r\n<\/ul>\r\n\r\n
          \r\n\"304\r\n<\/div>\r\n\r\n
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          316 Stainless Steel: Marine & Medical Grade<\/h2>\r\n

          316 stainless steel<\/strong> (marine grade stainless steel) is an upgraded austenitic grade with 2\u20133% molybdenum (Mo)<\/strong>.<\/p>\r\n\r\n

          Chemical Composition<\/h3>\r\n
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          • Chromium: 16\u201318%<\/li>\r\n
          • Nickel: 10\u201314%<\/li>\r\n
          • Molybdenum: 2\u20133%<\/li>\r\n<\/ul>\r\n\r\n

            Key Benefits<\/h3>\r\n
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            • \u2705 Superior corrosion resistance (pitting\/crevice)<\/li>\r\n
            • \u2705 Resists saltwater, chemicals, acids<\/li>\r\n
            • \u2705 Medical-grade biocompatible<\/li>\r\n
            • \u2705 High-temperature strength<\/li>\r\n<\/ul>\r\n\r\n

              Common Applications<\/h3>\r\n
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              • Marine parts, seawater equipment<\/li>\r\n
              • Medical implants, surgical tools<\/li>\r\n
              • Chemical processing parts<\/li>\r\n
              • Pharmaceutical equipment<\/li>\r\n
              • High-corrosion industrial components<\/li>\r\n<\/ul>\r\n\r\n
                \r\n\"316\r\n<\/div>\r\n\r\n
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                18-8 vs 304 vs 316: Side-by-Side Comparison<\/h2>\r\n
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                Grade<\/th>\r\nCorrosion<\/th>\r\nMachining<\/th>\r\nCost<\/th>\r\nBest For<\/th>\r\n<\/tr>\r\n
                18-8 \/ 304<\/td>\r\nGood<\/td>\r\nEasy<\/td>\r\nLow<\/td>\r\nGeneral, Food<\/td>\r\n<\/tr>\r\n
                316<\/td>\r\nExcellent<\/td>\r\nHard<\/td>\r\nHigh<\/td>\r\nMarine, Medical<\/td>\r\n<\/tr>\r\n<\/table>\r\n<\/div>\r\n\r\n
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                Get Expert Stainless Steel CNC Machining Support<\/h2>\r\n

                Choosing between 304, 316, and 18-8 stainless steel<\/strong> depends on your environment, function, budget, and machining requirements<\/strong>.<\/p>\r\n

                If you are unsure which grade fits your project, send your 2D drawings and 3D CAD files<\/strong>. Our CNC engineers provide free material recommendation, DFM analysis, and cost optimization<\/strong> for stainless steel CNC parts.<\/p>\r\n

                We specialize in precision CNC machining for medical, marine, food, and industrial stainless steel components<\/strong>\u2014prototypes to mass production.<\/p>\r\n\r\n<\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"

                Introduction When selecting stainless steel for CNC machined parts, the most common confusion is between 304 stainless steel, 316 stainless steel, and 18-8 stainless steel. Engineers and buyers often mix up these grades, which directly impacts corrosion resistance, machining difficulty, part quality, and cost. This guide breaks down 18-8 vs 304 vs 316 stainless steel […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_angie_page":false,"_gspb_post_css":"","page_builder":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-4626","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"blocksy_meta":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/posts\/4626","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/comments?post=4626"}],"version-history":[{"count":4,"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/posts\/4626\/revisions"}],"predecessor-version":[{"id":4630,"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/posts\/4626\/revisions\/4630"}],"wp:attachment":[{"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/media?parent=4626"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/categories?post=4626"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/haomaerprecision.com\/zh\/wp-json\/wp\/v2\/tags?post=4626"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}