{"id":5724,"date":"2026-05-14T16:44:08","date_gmt":"2026-05-14T08:44:08","guid":{"rendered":"https:\/\/xzfastener.com\/?post_type=product&p=5724"},"modified":"2026-05-14T16:44:09","modified_gmt":"2026-05-14T08:44:09","slug":"bs-4395-high-strength-hex-structural-bolt-black-oxide-carbon-steel-m3-thread-fastener","status":"publish","type":"product","link":"https:\/\/xzfastener.com\/vi\/products\/bs-4395-high-strength-hex-structural-bolt-black-oxide-carbon-steel-m3-thread-fastener\/","title":{"rendered":"BS 4395 High Strength Hex Structural Bolt Black Oxide Carbon Steel M3 Thread Fastener"},"content":{"rendered":"

Product Description<\/h2>\n

The BS 4395 High Strength Hex Structural Bolt with Black Oxide Finish<\/strong> is a durable fastening solution designed for machinery assembly, steel structure connections, industrial equipment, automotive components, and general engineering applications. Manufactured from high strength carbon steel<\/strong>, this bolt offers reliable mechanical strength, stable fastening performance, and strong resistance to loosening under demanding working conditions.<\/p>\n

This bolt features a hexagonal head<\/strong>, a smooth shank section, and a precision-machined metric thread. The hex head allows easy tightening with standard spanners, sockets, or power tools. The partially threaded design helps provide better shear resistance and improved structural connection performance compared with fully threaded bolts in certain applications.<\/p>\n

The Black Oxide Finish<\/strong> gives the bolt a dark black appearance and provides mild corrosion resistance when combined with protective oil. It is commonly used for high strength bolts, machinery fasteners, industrial hardware, and applications where a black surface finish is preferred.<\/p>\n

\n

Key Features<\/h2>\n
    \n
  • BS 4395 style high strength hex structural bolt<\/li>\n
  • Made from high strength carbon steel<\/li>\n
  • Black Oxide Finish for a dark industrial appearance<\/li>\n
  • Hex head design for easy installation<\/li>\n
  • Partial thread design for strong structural fastening<\/li>\n
  • Suitable for machinery, steel structure, equipment, and automotive use<\/li>\n
  • OEM and ODM customization available<\/li>\n
  • Available in different sizes, lengths, grades, and packaging options<\/li>\n<\/ul>\n
    \n

    Product Specifications<\/h2>\n
    \n
    \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
    Item<\/th>\nSpecification<\/th>\n<\/tr>\n<\/thead>\n
    Product Name<\/td>\nHigh Strength Hex Structural Bolt<\/td>\n<\/tr>\n
    Standard<\/td>\nBS 4395<\/td>\n<\/tr>\n
    Thread Size<\/td>\nM3 \/ Customized Sizes Available<\/td>\n<\/tr>\n
    Material<\/td>\nCarbon Steel<\/td>\n<\/tr>\n
    Surface Treatment<\/td>\nBlack Oxide Finish<\/td>\n<\/tr>\n
    Head Type<\/td>\nHex Head<\/td>\n<\/tr>\n
    Thread Type<\/td>\nMetric Thread<\/td>\n<\/tr>\n
    Thread Design<\/td>\nPartial Thread \/ Full Thread Optional<\/td>\n<\/tr>\n
    Strength Grade<\/td>\nHigh Strength Grade Available<\/td>\n<\/tr>\n
    Color<\/td>\nBlack<\/td>\n<\/tr>\n
    Application<\/td>\nSteel Structure, Machinery, Construction, Equipment Assembly<\/td>\n<\/tr>\n
    Custom Service<\/td>\nOEM \/ ODM Supported<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
    \n

    Surface Treatment: Black Oxide Finish<\/h2>\n

    The Black Oxide Finish<\/strong> is a common surface treatment for carbon steel and alloy steel fasteners. It creates a black surface layer on the bolt, improving appearance and providing basic anti-rust protection when used with oil or other protective coatings.<\/p>\n

    \n
    \n\n\n\n\n\n\n\n\n\n
    Surface Finish<\/th>\nAppearance<\/th>\nCorrosion Resistance<\/th>\nCommon Use<\/th>\n<\/tr>\n<\/thead>\n
    Black Oxide Finish<\/td>\nBlack \/ Dark Black<\/td>\nBasic, usually with oil protection<\/td>\nHigh strength bolts, machinery fasteners<\/td>\n<\/tr>\n
    Black Phosphate<\/td>\nMatte Black \/ Dark Gray<\/td>\nBetter than plain black oxide in some cases<\/td>\nAutomotive and industrial bolts<\/td>\n<\/tr>\n
    Zinc Plated<\/td>\nSilver \/ White Zinc<\/td>\nGeneral rust protection<\/td>\nStandard hardware fasteners<\/td>\n<\/tr>\n
    Hot Dip Galvanized<\/td>\nGray \/ Rough Silver<\/td>\nStrong outdoor corrosion resistance<\/td>\nOutdoor steel structures<\/td>\n<\/tr>\n
    Plain Finish<\/td>\nNatural Steel Color<\/td>\nLow<\/td>\nTemporary or internal applications<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
    \n

    Product Advantages<\/h2>\n
    \n
    \n\n\n\n\n\n\n\n\n\n\n
    Advantage<\/th>\nDescription<\/th>\n<\/tr>\n<\/thead>\n
    High Strength Material<\/td>\nCarbon steel provides reliable mechanical strength for heavy-duty fastening.<\/td>\n<\/tr>\n
    Black Surface Appearance<\/td>\nBlack oxide finish gives the bolt a clean, dark, industrial look.<\/td>\n<\/tr>\n
    Easy Installation<\/td>\nHex head design allows quick tightening with standard tools.<\/td>\n<\/tr>\n
    Strong Structural Connection<\/td>\nPartial thread design helps improve shear resistance in suitable applications.<\/td>\n<\/tr>\n
    Customizable Production<\/td>\nSize, length, thread, grade, finish, and packaging can be customized.<\/td>\n<\/tr>\n
    Cost-Effective Fastener<\/td>\nCarbon steel construction offers a good balance between strength and price.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
    \n

    Common Applications<\/h2>\n

    The BS 4395 High Strength Hex Structural Bolt with Black Oxide Finish<\/strong> is widely used in industrial and mechanical fastening systems.<\/p>\n

    \n
    \n\n\n\n\n\n\n\n\n\n\n
    Industry<\/th>\nTypical Application<\/th>\n<\/tr>\n<\/thead>\n
    Steel Structure<\/td>\nSteel frame assembly, beam connection, bracket fixing<\/td>\n<\/tr>\n
    Machinery<\/td>\nMachine body assembly, equipment installation, mechanical connection<\/td>\n<\/tr>\n
    Construction<\/td>\nSupport frames, metal plates, structural components<\/td>\n<\/tr>\n
    Automotive<\/td>\nChassis parts, brackets, engine-related components<\/td>\n<\/tr>\n
    Industrial Equipment<\/td>\nProduction equipment, machine base, support systems<\/td>\n<\/tr>\n
    General Engineering<\/td>\nRepair, maintenance, custom metal fabrication<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
    \n

    Material and Custom Options<\/h2>\n
    \n
    \n\n\n\n\n\n\n\n\n\n\n\n
    Custom Item<\/th>\nAvailable Options<\/th>\n<\/tr>\n<\/thead>\n
    Material<\/td>\nCarbon Steel, Alloy Steel, Stainless Steel<\/td>\n<\/tr>\n
    Size<\/td>\nM3, M4, M5, M6, M8, M10, M12, M16, M20, Custom<\/td>\n<\/tr>\n
    Length<\/td>\nAccording to customer drawing or sample<\/td>\n<\/tr>\n
    Thread Type<\/td>\nCoarse Thread, Fine Thread, Full Thread, Partial Thread<\/td>\n<\/tr>\n
    Surface Finish<\/td>\nBlack Oxide, Black Phosphate, Zinc Plated, HDG, Plain<\/td>\n<\/tr>\n
    Strength Grade<\/td>\n8.8, 10.9, 12.9, Customized Grade<\/td>\n<\/tr>\n
    Packaging<\/td>\nBulk Carton, Small Box, Plastic Bag, Pallet, Customized Packing<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
    \n

    Why Choose Black Oxide Hex Structural Bolts?<\/h2>\n

    Black oxide hex bolts are commonly selected when customers need a dark surface finish<\/strong>, good dimensional accuracy, and reliable fastening performance. Compared with thick coatings such as hot dip galvanizing, black oxide creates a thinner surface layer, which helps maintain better thread accuracy.<\/p>\n

    For high strength bolts, black oxide is often used together with protective oil to reduce surface oxidation during storage and transportation. It is suitable for indoor machinery, equipment assembly, automotive parts, and general industrial applications.<\/p>\n

    \n

    Quality Control<\/h2>\n
    \n
    \n\n\n\n\n\n\n\n\n\n\n
    Inspection Item<\/th>\nPurpose<\/th>\n<\/tr>\n<\/thead>\n
    Dimension Inspection<\/td>\nCheck head size, shank diameter, length, and thread length<\/td>\n<\/tr>\n
    Thread Gauge Test<\/td>\nEnsure thread accuracy and nut compatibility<\/td>\n<\/tr>\n
    Hardness Test<\/td>\nVerify mechanical strength and material performance<\/td>\n<\/tr>\n
    Tensile Test<\/td>\nConfirm load-bearing capacity<\/td>\n<\/tr>\n
    Surface Inspection<\/td>\nCheck black oxide appearance and finish quality<\/td>\n<\/tr>\n
    Packaging Inspection<\/td>\nEnsure safe packing for storage and shipping<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
    \n

    FAQ<\/h2>\n

    1. What is a Black Oxide Finish?<\/h3>\n

    Black oxide is a chemical surface treatment that forms a black layer on carbon steel or alloy steel fasteners. It improves appearance and provides basic corrosion resistance, especially when combined with protective oil.<\/p>\n

    2. Is Black Oxide better than zinc plating?<\/h3>\n

    Black oxide provides a dark appearance and better dimensional accuracy because the coating layer is very thin. Zinc plating usually offers better corrosion resistance, while black oxide is more commonly used for high strength and machinery fasteners.<\/p>\n

    3. Can black oxide bolts be used outdoors?<\/h3>\n

    Black oxide bolts are mainly recommended for indoor or low-corrosion environments. For outdoor, humid, or marine environments, hot dip galvanized, zinc plated, or stainless steel bolts are usually better choices.<\/p>\n

    4. What material is this bolt made from?<\/h3>\n

    This bolt is made from high strength carbon steel<\/strong>. Alloy steel and stainless steel versions can also be supplied according to customer requirements.<\/p>\n

    5. Is this bolt fully threaded or partially threaded?<\/h3>\n

    The product shown is a partially threaded hex bolt<\/strong>. Full thread versions can also be customized if required.<\/p>\n

    6. Can you supply matching nuts and washers?<\/h3>\n

    Yes. We can supply matching hex nuts, heavy hex nuts, flat washers, spring washers, and complete bolt-nut-washer assemblies.<\/p>\n

    7. Can the size be customized?<\/h3>\n

    Yes. We can customize size, length, thread pitch, material, strength grade, surface treatment, and packaging according to drawings, samples, or customer specifications.<\/p>\n

    8. What information is needed for a quotation?<\/h3>\n

    Please provide the bolt size, length, thread type, material, grade, surface finish, quantity, packaging requirement, and destination port or delivery address.<\/p>\n

    \n

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    BS 4395 high strength hex structural bolt made from black oxide carbon steel with M3 metric thread. Durable industrial fastener for machinery, steel structures, construction, automotive parts, and equipment assembly.<\/strong><\/p>","protected":false},"featured_media":5725,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"fastener-coating":[142,34,150],"fastener-material":[42],"fastener-type":[53,474],"product_brand":[],"product_cat":[22,29],"product_tag":[],"class_list":{"0":"post-5724","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"fastener-coating-black-oxide","7":"fastener-coating-blackening","8":"fastener-coating-custom-color-coating","9":"fastener-material-carbon-steel","10":"fastener-type-bolts","11":"fastener-type-hex-head-bolt","12":"product_cat-standard-fasteners","13":"product_cat-various-coated-fasteners","15":"first","16":"instock","17":"shipping-taxable","18":"product-type-simple"},"acf":[],"_links":{"self":[{"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/product\/5724","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/comments?post=5724"}],"version-history":[{"count":1,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/product\/5724\/revisions"}],"predecessor-version":[{"id":5726,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/product\/5724\/revisions\/5726"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/media\/5725"}],"wp:attachment":[{"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/media?parent=5724"}],"wp:term":[{"taxonomy":"fastener-coating","embeddable":true,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/fastener-coating?post=5724"},{"taxonomy":"fastener-material","embeddable":true,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/fastener-material?post=5724"},{"taxonomy":"fastener-type","embeddable":true,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/fastener-type?post=5724"},{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/product_brand?post=5724"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/product_cat?post=5724"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/xzfastener.com\/vi\/wp-json\/wp\/v2\/product_tag?post=5724"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}