{"product_id":"stainless-steel-sheet-bright-polish-12mm-thick-grade-304-a2","title":"Stainless Steel Sheet Bright Polish 12mm Thick Many Size Grade A2 304 L50-450mm","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003ch2\u003eStainless Steel Sheet 12mm Thick — Grade 304 A2, Bright Polished Finish for Reliable DIY Fabrication\u003c\/h2\u003e\n    \u003cp\u003eWhen a project demands a flat metal surface that holds up to moisture, mechanical stress, and everyday wear, thin sheet metal often falls short. Fabricators, metalworkers, and serious DIYers who need a rigid, corrosion-resistant base turn to a 12mm thick stainless steel sheet — a gauge that delivers structural integrity without requiring industrial cutting equipment.\u003c\/p\u003e\n    \u003cp\u003eThese stainless steel sheets are manufactured to Grade 304 (A2) specification, the most widely used austenitic stainless alloy. Each piece features a bright polished surface finish on the face side. Thickness is a consistent 12mm (~0.47 in) across all sizes. Available dimensions range from 50×50mm (~2×2 in) up to 450×450mm (~17.7×17.7 in), with rectangular and square options in between.\u003c\/p\u003e\n    \u003cp\u003eTypical applications include custom machine guards and enclosure panels, structural backing plates for welding fixtures, DIY workbench inserts and surface plates, and architectural accent pieces where a mirror-adjacent finish is needed. The 304 alloy's chromium content makes these sheets well-suited for outdoor signage brackets, marine-adjacent environments, and food-contact fabrication projects.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-compat\"\u003e\n    \u003cspan class=\"hdiy-compat-icon\"\u003e🔩\u003c\/span\u003e\n    \u003cstrong\u003eCompatibility:\u003c\/strong\u003e Suitable for welding (TIG\/MIG), drilling, grinding, and mechanical fastening. Compatible with standard stainless steel hardware (M4–M12 fasteners). Not recommended for applications requiring Grade 316 marine-grade resistance.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-features\"\u003e\n    \u003ch2\u003e✅ Key Features of These Stainless Steel Sheets\u003c\/h2\u003e\n    \u003cdiv class=\"hdiy-list\"\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🏗️\u003c\/span\u003e\n        \u003cstrong\u003e12mm Structural Thickness\u003c\/strong\u003e\n        \u003cp\u003eAt 12mm (~0.47 in), these sheets resist flex and deformation under load — suitable for backing plates, mounting surfaces, and load-bearing brackets where thinner gauges would deflect.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔬\u003c\/span\u003e\n        \u003cstrong\u003eGrade 304 A2 Alloy\u003c\/strong\u003e\n        \u003cp\u003eContains 18% chromium and 8% nickel, giving the steel its passive oxide layer. This layer self-repairs when scratched, maintaining corrosion resistance in humid, wet, and mildly acidic environments.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e✨\u003c\/span\u003e\n        \u003cstrong\u003eBright Polished Surface\u003c\/strong\u003e\n        \u003cp\u003eThe face side is bright polished, reducing surface roughness and making the sheet easier to clean. Suitable for visible installations where a reflective, smooth appearance is required.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\n        \u003cstrong\u003e13 Size Options — 50mm to 450mm\u003c\/strong\u003e\n        \u003cp\u003eChoose from square and rectangular cuts ranging from 50×50mm up to 450×450mm. Select the size closest to your finished dimension to minimize cutting waste on your end.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e⚙️\u003c\/span\u003e\n        \u003cstrong\u003eMachinable and Weldable\u003c\/strong\u003e\n        \u003cp\u003e304 stainless machines cleanly with carbide tooling and welds with standard TIG or MIG processes. Drill, tap, grind, or cut with an angle grinder fitted with a stainless-rated disc.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\n        \u003cstrong\u003eSingle or Paired Quantity Options\u003c\/strong\u003e\n        \u003cp\u003eThe 50×50mm size is available in a pack of 2, making it practical for symmetrical mounting applications such as corner brackets or paired standoffs. All other sizes ship as individual pieces.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-table-wrap\"\u003e\n    \u003ch2\u003e📐 Technical Specifications — Stainless Steel Sheet\u003c\/h2\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eStainless Steel Grade 304 (A2)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eSurface Finish\u003c\/th\u003e\n\u003ctd\u003eBright Polished\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eThickness\u003c\/th\u003e\n\u003ctd\u003e12mm (approx. 0.47 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eAvailable Sizes (L × W)\u003c\/th\u003e\n\u003ctd\u003e50×50mm up to 450×450mm — See variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eQuantity per Order\u003c\/th\u003e\n\u003ctd\u003eSee variant options (1 or 2 pieces)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eChromium Content\u003c\/th\u003e\n\u003ctd\u003eTypically 17.5–18.5%\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eNickel Content\u003c\/th\u003e\n\u003ctd\u003eTypically 8.0–10.5%\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003eSee variant options (varies by size)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eWeldability\u003c\/th\u003e\n\u003ctd\u003eTIG \/ MIG compatible\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eMachinability\u003c\/th\u003e\n\u003ctd\u003eCarbide tooling recommended\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eMagnetism\u003c\/th\u003e\n\u003ctd\u003eNon-magnetic (austenitic)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eOperating Temperature\u003c\/th\u003e\n\u003ctd\u003eUp to approximately 870°C (1600°F) continuous\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-faq\"\u003e\n    \u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhich size should I choose for my project?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eSelect the size that is equal to or slightly larger than your finished cut dimension. For example, if your finished part is 90×90mm, choose the 100×100mm sheet and trim to fit. Cutting stainless steel 12mm thick requires an angle grinder with a stainless-rated cutting disc, a cold saw, or a plasma cutter — standard wood saws will not work.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eIs Grade 304 stainless steel strong enough for structural use?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eGrade 304 has a tensile strength of approximately 515 MPa (75,000 psi) and a yield strength of around 205 MPa (30,000 psi). At 12mm thickness, these sheets are suitable for backing plates, mounting flanges, and light structural brackets. For applications subject to heavy dynamic loads or impact, consult a structural engineer to confirm suitability.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWill these sheets rust or corrode outdoors?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eGrade 304 stainless steel resists rust in most outdoor environments due to its passive chromium oxide layer. However, in coastal or high-chloride environments (salt spray, de-icing salts), surface staining or pitting can occur over time. For those conditions, Grade 316 stainless is the recommended alternative. In standard outdoor or indoor-wet environments, 304 performs reliably without additional coating.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan I weld these sheets to other stainless steel components?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. Grade 304 welds well using TIG (GTAW) or MIG (GMAW) processes with ER308L filler wire. At 12mm thickness, use adequate heat input and consider back-purging with argon to prevent oxidation on the reverse side. Post-weld passivation (citric or nitric acid treatment) is recommended to restore the corrosion-resistant surface in the heat-affected zone.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eIs the bright polished finish on both sides?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe bright polished finish is applied to the face side of the sheet. The reverse side typically has a mill or ground finish. If a polished appearance is required on both faces (for example, in a visible architectural installation), plan to polish the reverse side yourself using progressively finer abrasive pads or a polishing wheel.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eHow do I drill or tap holes in a 12mm stainless steel sheet?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eUse sharp carbide-tipped drill bits rated for stainless steel. Drill at a slow speed (typically 300–600 RPM for holes under 10mm) with steady feed pressure and cutting fluid or oil to prevent work-hardening. For tapping, use a spiral-flute tap with cutting oil and back off every half-turn to clear chips. Avoid high-speed steel (HSS) bits without cobalt content — they dull quickly on 304 stainless.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat is the difference between Grade 304 and Grade 316 stainless steel?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eBoth are austenitic stainless steels, but Grade 316 adds 2–3% molybdenum, which significantly improves resistance to chloride pitting and crevice corrosion. For most indoor, food-service, and general outdoor applications, 304 is sufficient and more cost-effective. Choose 316 if the sheet will be in direct contact with salt water, chlorinated water, or industrial chemicals containing chlorides.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-cta\"\u003e\n    🛒 Select your size and quantity above, then add to cart.\n  \u003c\/div\u003e\n\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Which size should I choose for my project?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Select the size that is equal to or slightly larger than your finished cut dimension. For example, if your finished part is 90×90mm, choose the 100×100mm sheet and trim to fit. Cutting stainless steel 12mm thick requires an angle grinder with a stainless-rated cutting disc, a cold saw, or a plasma cutter.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is Grade 304 stainless steel strong enough for structural use?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Grade 304 has a tensile strength of approximately 515 MPa and a yield strength of around 205 MPa. At 12mm thickness, these sheets are suitable for backing plates, mounting flanges, and light structural brackets.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will these sheets rust or corrode outdoors?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Grade 304 stainless steel resists rust in most outdoor environments. In coastal or high-chloride environments, surface staining or pitting can occur over time. For those conditions, Grade 316 stainless is the recommended alternative.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I weld these sheets to other stainless steel components?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Grade 304 welds well using TIG or MIG processes with ER308L filler wire. Post-weld passivation is recommended to restore the corrosion-resistant surface in the heat-affected zone.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is the bright polished finish on both sides?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The bright polished finish is applied to the face side of the sheet. The reverse side typically has a mill or ground finish.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do I drill or tap holes in a 12mm stainless steel sheet?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Use sharp carbide-tipped drill bits rated for stainless steel. Drill at a slow speed with cutting fluid. For tapping, use a spiral-flute tap with cutting oil and back off every half-turn to clear chips.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the difference between Grade 304 and Grade 316 stainless steel?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Grade 316 adds 2–3% molybdenum, which improves resistance to chloride pitting and crevice corrosion. For most indoor and general outdoor applications, 304 is sufficient. Choose 316 for direct contact with salt water or industrial chloride chemicals.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"50mm X 50mm X 12mm \/ 2","offer_id":52379020394770,"sku":"WWLFABGQJDWW172x1","price":56.7,"currency_code":"USD","in_stock":true},{"title":"100mm X 50mm X 12mm \/ 1","offer_id":52379020427538,"sku":"WWLFABGQJDWW173x1","price":54.13,"currency_code":"USD","in_stock":true},{"title":"100mm X 100mm X 12mm \/ 1","offer_id":52379020460306,"sku":"WWLFABGQJDWW174x1","price":103.99,"currency_code":"USD","in_stock":true},{"title":"200mm X 100mm X 12mm \/ 1","offer_id":52379020493074,"sku":"WWLFABGQJDWW175x1","price":196.75,"currency_code":"USD","in_stock":true},{"title":"200mm X 200mm X 12mm \/ 1","offer_id":52379020525842,"sku":"WWLFABGQJDWW176x1","price":388.81,"currency_code":"USD","in_stock":true},{"title":"300mm X 200mm X 12mm \/ 1","offer_id":52379020558610,"sku":"WWLFABGQJDWW177x1","price":580.8,"currency_code":"USD","in_stock":true},{"title":"300mm X 300mm X 12mm \/ 1","offer_id":52379020591378,"sku":"WWLFABGQJDWW178x1","price":868.54,"currency_code":"USD","in_stock":true},{"title":"400mm X 300mm X 12mm \/ 1","offer_id":52379020624146,"sku":"WWLFABGQJDWW179x1","price":1140.6,"currency_code":"USD","in_stock":true},{"title":"400mm X 400mm X 12mm \/ 1","offer_id":52379020656914,"sku":"WWLFABGQJDWW180x1","price":1518.9,"currency_code":"USD","in_stock":true},{"title":"150mm X 150mm X 12mm \/ 1","offer_id":52379020689682,"sku":"WWLFABGQJDWW181x1","price":220.63,"currency_code":"USD","in_stock":true},{"title":"250mm X 250mm X 12mm \/ 1","offer_id":52379020722450,"sku":"WWLFABGQJDWW182x1","price":604.93,"currency_code":"USD","in_stock":true},{"title":"350mm X 350mm X 12mm \/ 1","offer_id":52379020755218,"sku":"WWLFABGQJDWW183x1","price":1166.3,"currency_code":"USD","in_stock":true},{"title":"450mm X 450mm X 12mm \/ 1","offer_id":52379020787986,"sku":"WWLFABGQJDWW184x1","price":1919.78,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Main-01_77ce4127-28e6-49cb-aeb6-036fbf90579d.jpg?v=1781770737","url":"https:\/\/homediyer.com\/de\/products\/stainless-steel-sheet-bright-polish-12mm-thick-grade-304-a2","provider":"HomeDIYer","version":"1.0","type":"link"}