{"product_id":"si3n4-full-ceramic-bearings-silicon-nitride-cage-id-3-40mm","title":"Ball Bearings Silicon Nitride Cage Full Ceramic Bearings ID 3-40MM Si3N4 Bearing","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eSi3N4 Full Ceramic Bearings with Silicon Nitride Cage — Built for Extreme Conditions\u003c\/h2\u003e\n\u003cp\u003eWhen standard steel bearings fail under heat, corrosion, or electrical interference, engineers and precision equipment builders turn to full ceramic bearings. These Si3N4 silicon nitride ceramic bearings with silicon nitride cage are engineered for applications where metal simply cannot perform — from chemical processing equipment to high-speed spindles and vacuum systems.\u003c\/p\u003e\n\u003cp\u003eEach bearing is constructed entirely from silicon nitride (Si3N4) ceramic — balls, inner race, outer race, and cage — with no metallic components. Available in inner diameter sizes from 3mm (~0.12 in) to 40mm (~1.57 in), with a range of outer diameter and thickness combinations to suit your specific bore and housing requirements. See variant options for the full dimensional matrix.\u003c\/p\u003e\n\u003cp\u003eTypical use cases include high-speed dental and medical handpieces requiring non-magnetic, sterilizable bearings; semiconductor and cleanroom equipment where particle contamination must be minimized; chemical pumps and flow meters exposed to aggressive media; and high-temperature kiln or furnace conveyor systems where lubricant breakdown is a concern.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e⚙️\u003c\/span\u003e \u003cstrong\u003eCompatibility:\u003c\/strong\u003e These are full ceramic open bearings. Verify your bore ID, housing OD, and axial space (thickness) before ordering. No metallic retainer — suitable for non-magnetic and electrically insulating applications.\u003c\/div\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These Si3N4 Full Ceramic Bearings\u003c\/h2\u003e\n\u003cul class=\"hdiy-list\"\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔥\u003c\/span\u003e\u003cstrong\u003eHigh-Temperature Resistance:\u003c\/strong\u003e Silicon nitride retains structural integrity at temperatures up to approximately 1000°C, far exceeding the limits of steel or hybrid ceramic bearings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🧪\u003c\/span\u003e\u003cstrong\u003eChemical Corrosion Resistance:\u003c\/strong\u003e Si3N4 ceramic is inert to most acids, alkalis, and solvents, making these bearings suitable for chemical processing, marine, and wet environments without protective coatings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚡\u003c\/span\u003e\u003cstrong\u003eElectrically Non-Conductive:\u003c\/strong\u003e The all-ceramic construction provides full electrical insulation, eliminating current leakage paths — critical in electric motors, generators, and semiconductor fabrication equipment.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🧲\u003c\/span\u003e\u003cstrong\u003eNon-Magnetic:\u003c\/strong\u003e Zero ferrous content means no magnetic interference, making these bearings compatible with MRI-adjacent equipment, scientific instruments, and magnetically sensitive assemblies.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚖️\u003c\/span\u003e\u003cstrong\u003eLow Density, Reduced Centrifugal Load:\u003c\/strong\u003e Si3N4 is approximately 60% lighter than bearing steel, reducing centrifugal forces on the raceway at high RPM and enabling higher operating speeds with lower heat generation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔧\u003c\/span\u003e\u003cstrong\u003eWide Size Range — ID 3mm to 40mm:\u003c\/strong\u003e With 47 size variants spanning 3×8×3mm through 40×68×15mm, you can source the exact dimensional fit for miniature instrument bearings through medium-load industrial applications from a single listing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — Si3N4 Full Ceramic Bearings\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eSilicon Nitride (Si3N4) — balls, races, and cage\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCage Material\u003c\/th\u003e\n\u003ctd\u003eSilicon Nitride (Si3N4) — full ceramic cage\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eInner Diameter (ID) Range\u003c\/th\u003e\n\u003ctd\u003e3mm – 40mm (approx. 0.12 in – 1.57 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOuter Diameter (OD) Range\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eThickness Range\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBearing Type\u003c\/th\u003e\n\u003ctd\u003eDeep groove ball bearing, open (no seal\/shield)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOperating Temperature\u003c\/th\u003e\n\u003ctd\u003eUp to approximately 1000°C (1832°F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eElectrical Conductivity\u003c\/th\u003e\n\u003ctd\u003eNon-conductive (full ceramic)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMagnetic Properties\u003c\/th\u003e\n\u003ctd\u003eNon-magnetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eLubrication\u003c\/th\u003e\n\u003ctd\u003eDry \/ self-lubricating (no grease required)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCorrosion Resistance\u003c\/th\u003e\n\u003ctd\u003eResistant to most acids, alkalis, and solvents\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHardness\u003c\/th\u003e\n\u003ctd\u003eApproximately HV 1400–1600 (Vickers)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDensity\u003c\/th\u003e\n\u003ctd\u003eApproximately 3.2 g\/cm³\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of Size Variants\u003c\/th\u003e\n\u003ctd\u003e47 (3×8×3mm through 40×68×15mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-faq\"\u003e\n\u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I choose the right size bearing for my application?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eMatch the inner diameter (ID) to your shaft diameter, the outer diameter (OD) to your housing bore, and the thickness to your available axial space. Use the variant selector — each option is listed as ID × OD × Thickness in millimeters. If your shaft is imperial, convert: 1 inch = 25.4mm. When in doubt between two sizes, choose the one where the ID is a snug interference or light press fit on the shaft.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan these bearings run without lubrication?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes. Silicon nitride ceramic has inherent dry-running capability due to its low friction coefficient and self-lubricating surface properties. These bearings are commonly used in vacuum environments, cleanrooms, and food-processing equipment where grease or oil contamination is unacceptable. For very high-speed applications, a small amount of compatible dry lubricant (e.g., PTFE-based) can further extend service life.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eAre these bearings suitable for use in corrosive chemical environments?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eSi3N4 ceramic is chemically inert to most common acids (including hydrochloric and sulfuric acid at moderate concentrations), alkalis, and organic solvents. It is not recommended for use with hydrofluoric acid (HF) or concentrated phosphoric acid at elevated temperatures, which can attack silicon nitride. For specific chemical compatibility, contact us to confirm suitability for your media.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the maximum operating temperature for Si3N4 ceramic bearings?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eSilicon nitride retains its mechanical properties up to approximately 1000°C (1832°F) in non-oxidizing environments. In air, oxidation of the surface begins above approximately 800°C but typically forms a protective silica layer that limits further degradation. This makes Si3N4 bearings suitable for kiln conveyors, furnace equipment, and high-temperature process machinery where steel bearings would fail due to tempering or lubricant breakdown.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eAre these bearings compatible with MRI machines or magnetically sensitive equipment?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes. Because the entire bearing — balls, races, and cage — is made from silicon nitride ceramic with zero ferrous content, these bearings are fully non-magnetic. They are used in MRI-adjacent positioning systems, scientific instruments, and electromagnetic research equipment where even trace magnetic permeability would cause interference or measurement errors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do full ceramic Si3N4 bearings compare to hybrid ceramic bearings?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eHybrid ceramic bearings use Si3N4 balls but retain steel inner and outer races. Full ceramic bearings (like these) use Si3N4 for all components including the cage. Full ceramic bearings offer complete electrical insulation, full corrosion resistance across all surfaces, and non-magnetic properties throughout — whereas hybrid bearings retain the electrical conductivity and corrosion vulnerability of their steel races. Full ceramic is the correct choice when the application demands total isolation from conductivity, magnetism, or chemical attack.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat load types are these bearings designed for?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThese are deep groove ball bearings, which handle primarily radial loads with moderate axial (thrust) loads in both directions. They are not designed for heavy axial-only or shock loading. Si3N4 ceramic, while extremely hard, is more brittle than steel — avoid impact loads or press-fitting with excessive force. Use a bearing press or appropriate installation tooling and apply force only to the race being fitted.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your ID × OD × Thickness above, then add to cart.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"HomeDIYer","offers":[{"title":"3x8x3mm","offer_id":52410249806098,"sku":"GLFBWJJGLBZSJ056967x1","price":30.87,"currency_code":"USD","in_stock":true},{"title":"3x9x3mm","offer_id":52410249838866,"sku":"GLFBWJJGLBZSJ056974x1","price":33.42,"currency_code":"USD","in_stock":true},{"title":"4x11x4mm","offer_id":52410249871634,"sku":"GLFBWJJGLBZSJ056968x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"4x12x4mm","offer_id":52410249904402,"sku":"GLFBWJJGLBZSJ056975x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"5x13x4mm","offer_id":52410249937170,"sku":"GLFBWJJGLBZSJ056969x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"5x14x5mm","offer_id":52410249969938,"sku":"GLFBWJJGLBZSJ056976x1","price":27.31,"currency_code":"USD","in_stock":true},{"title":"5x16x5mm","offer_id":52410250002706,"sku":"GLFBWJJGLSMZC0011x1","price":22.71,"currency_code":"USD","in_stock":true},{"title":"6x15x5mm","offer_id":52410250035474,"sku":"GLFBWJJGLBZSJ056970x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"6x17x6mm","offer_id":52410250068242,"sku":"GLFBWJJGLBZSJ056977x1","price":27.31,"currency_code":"USD","in_stock":true},{"title":"7x17x5mm","offer_id":52410250101010,"sku":"GLFBWJJGLBZSJ056971x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"7x19x6mm","offer_id":52410250133778,"sku":"GLFBWJJGLBZSJ056978x1","price":27.31,"currency_code":"USD","in_stock":true},{"title":"8x19x6mm","offer_id":52410250166546,"sku":"GLFBWJJGLBZSJ056972x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"8x22x7mm","offer_id":52410250199314,"sku":"GLFBWJJGLBZSJ056979x1","price":27.31,"currency_code":"USD","in_stock":true},{"title":"9x20x6mm","offer_id":52410250232082,"sku":"GLFBWJJGLBZSJ056973x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"9x24x7mm","offer_id":52410250264850,"sku":"GLFBWJJGLBZSJ056980x1","price":27.31,"currency_code":"USD","in_stock":true},{"title":"10x19x5mm","offer_id":52410250297618,"sku":"GLFBWJJGLBZSJ056981x1","price":24.25,"currency_code":"USD","in_stock":true},{"title":"10x30x9mm","offer_id":52410250330386,"sku":"GLFBWJJGLBZSJ056989x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"10x26x8mm","offer_id":52410250363154,"sku":"GLFBWJJGLBZSJ056996x1","price":24.75,"currency_code":"USD","in_stock":true},{"title":"10x22x6mm","offer_id":52410250395922,"sku":"GLFBWJJGLBZSJ057005x1","price":25.77,"currency_code":"USD","in_stock":true},{"title":"12x21x5mm","offer_id":52410250428690,"sku":"GLFBWJJGLBZSJ056982x1","price":25.77,"currency_code":"USD","in_stock":true},{"title":"12x32x10mm","offer_id":52410250461458,"sku":"GLFBWJJGLBZSJ056990x1","price":33.42,"currency_code":"USD","in_stock":true},{"title":"12x28x8mm","offer_id":52410250494226,"sku":"GLFBWJJGLBZSJ056997x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"12x24x6mm","offer_id":52410250526994,"sku":"GLFBWJJGLBZSJ057006x1","price":28.33,"currency_code":"USD","in_stock":true},{"title":"15x24x5mm","offer_id":52410250559762,"sku":"GLFBWJJGLBZSJ056983x1","price":29.35,"currency_code":"USD","in_stock":true},{"title":"15x35x11mm","offer_id":52410250592530,"sku":"GLFBWJJGLBZSJ056991x1","price":38.52,"currency_code":"USD","in_stock":true},{"title":"15x32x9mm","offer_id":52410250625298,"sku":"GLFBWJJGLBZSJ056998x1","price":30.87,"currency_code":"USD","in_stock":true},{"title":"15x28x7mm","offer_id":52410250658066,"sku":"GLFBWJJGLBZSJ057007x1","price":30.87,"currency_code":"USD","in_stock":true},{"title":"17x26x5mm","offer_id":52410250690834,"sku":"GLFBWJJGLBZSJ056984x1","price":30.87,"currency_code":"USD","in_stock":true},{"title":"17x40x12mm","offer_id":52410250723602,"sku":"GLFBWJJGLBZSJ056992x1","price":43.87,"currency_code":"USD","in_stock":true},{"title":"17x35x10mm","offer_id":52410250756370,"sku":"GLFBWJJGLBZSJ056999x1","price":38.52,"currency_code":"USD","in_stock":true},{"title":"17x30x7mm","offer_id":52410250789138,"sku":"GLFBWJJGLBZSJ057008x1","price":34.44,"currency_code":"USD","in_stock":true},{"title":"20x32x7mm","offer_id":52410250821906,"sku":"GLFBWJJGLBZSJ056985x1","price":40.56,"currency_code":"USD","in_stock":true},{"title":"20x47x14mm","offer_id":52410250854674,"sku":"GLFBWJJGLBZSJ056993x1","price":75.24,"currency_code":"USD","in_stock":true},{"title":"20x42x12mm","offer_id":52410250887442,"sku":"GLFBWJJGLBZSJ057000x1","price":46.88,"currency_code":"USD","in_stock":true},{"title":"20x37x9mm","offer_id":52410250920210,"sku":"GLFBWJJGLBZSJ057009x1","price":41.58,"currency_code":"USD","in_stock":true},{"title":"25x37x7mm","offer_id":52410250952978,"sku":"GLFBWJJGLBZSJ056986x1","price":50.25,"currency_code":"USD","in_stock":true},{"title":"25x52x15mm","offer_id":52410250985746,"sku":"GLFBWJJGLBZSJ056994x1","price":84.1,"currency_code":"USD","in_stock":true},{"title":"25x47x12mm","offer_id":52410251018514,"sku":"GLFBWJJGLBZSJ057001x1","price":53.05,"curren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