Excellent precision on DIN standards. The material certification was impeccable and arrived exactly as promised.
Hans Mueller
PrecisionAuto GmbH - Germany
Certified quality, high-volume production, and precision engineering since 1998. We supply the backbone of modern infrastructure.

12.9 Grade Black Zinc Plated Hex Head Bolts (DIN931 & DIN933)

HDG Hot-Dip Galvanized Round Head Guardrail Splicing Bolt
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Broadest inventory of industrial fasteners ready for worldwide dispatch.

These 8.8 grade black oxide hex head bolts comply with DIN933 full-thread and DIN931 half-thread standards. Made of premium carbon steel, they deliver stable high tensile strength and excellent oxidation resistance. Featuring precise standard threads for effortless installation, these durable fasteners fit machinery, construction, automotive and railway projects, with custom packaging and logos available.

These DIN931/DIN933 hex bolts come in 10.9 and 12.9 high strength grades with black zinc plated finish for superior rust and salt spray resistance. Made of premium alloy steel with high tensile and yield strength, they support full-thread and half-thread designs. Covering complete M4-M52 specifications, they are ideal for automotive, machinery, steel structure and new energy heavy-duty applications with custom options available.

Manufactured per DIN 912 standards, these 12.9-grade hex socket head cap screws are heat-treated from premium carbon steel for extreme hardness and strong vibration resistance. Featuring black oxide finish for upgraded wear and anti-rust performance, they fit high-precision, heavy-duty scenarios. Full M6-M36 size options and diverse surface treatments support custom industrial and engineering applications.

Compliant with DIN603 standards, these HDG carriage bolts are made of premium carbon steel in 4.8 and 6.8 grades. Featuring round head and square neck for anti-rotation locking, they ensure tight, stable connections. The hot-dip galvanized coating delivers excellent outdoor anti-corrosion performance. Suitable for construction, machinery, vehicle and agricultural machinery fastening with full size options and custom support.

These HDG round head guardrail bolts with matched nuts are tailor-made for fence and steel structure splicing. Made of premium carbon steel with hot-dip galvanized finish, they offer great outdoor rust resistance and stable tensile strength. Burr-free round head ensures safe installation. Multiple sizes and strength grades are available with custom services for various municipal and traffic projects.

These hot-dip galvanized expansion screws are high-performance anchoring fasteners made of premium carbon steel and manufactured per GB/T standards. Featuring uniform anti-corrosion galvanized coating and strong expansion gripping force, they deliver stable, slip-proof fixing. Available in full M8-M24 sizes, suitable for home decoration, industrial construction, medical equipment and ship fitting installation.
Need custom specifications? Contact our engineering team for technical guidance.
State-of-the-art facilities ensuring precision at every step.
100%
Inspection Rate
Our facility is equipped with state-of-the-art CNC machining centers and cold-forging lines. We specialize in high-volume production of fasteners across various materials.
Rigorous testing for tensile strength and corrosion resistance.
Advanced coating options: Zinc, Chrome, Nickel, and PTFE.
Verified experiences from our global manufacturing partners.
Excellent precision on DIN standards. The material certification was impeccable and arrived exactly as promised.
Hans Mueller
PrecisionAuto GmbH - Germany
Quality consistency is paramount for our robotics assembly line. The dimensional accuracy of their custom bolts is world-class.
Kenji Tanaka
Nippon Robotics Corp - Japan
Supply chain reliability is critical for our hub. Fasteners B2B has consistently met our lead times for high-volume orders.
Wei Chen
AeroLogic Asia - Singapore
Exceptional technical support. Their engineering team helped us optimize our fastener specifications for North Sea maritime environments.
Alistair Vance
Maritime Tech Ltd - United Kingdom
Reliable high-volume production. Their ability to scale for our automotive plant expansions has made them a key strategic partner.
Elena Rodriguez
AutoManufactura SA - Mexico
Excellent precision on DIN standards. The material certification was impeccable and arrived exactly as promised.
Hans Mueller
PrecisionAuto GmbH - Germany
Quality consistency is paramount for our robotics assembly line. The dimensional accuracy of their custom bolts is world-class.
Kenji Tanaka
Nippon Robotics Corp - Japan
Supply chain reliability is critical for our hub. Fasteners B2B has consistently met our lead times for high-volume orders.
Wei Chen
AeroLogic Asia - Singapore
Exceptional technical support. Their engineering team helped us optimize our fastener specifications for North Sea maritime environments.
Alistair Vance
Maritime Tech Ltd - United Kingdom
Reliable high-volume production. Their ability to scale for our automotive plant expansions has made them a key strategic partner.
Elena Rodriguez
AutoManufactura SA - Mexico
Answers to common technical and logistics inquiries.
Our MOQ varies by product category. For standard fasteners, it generally starts at 10,000 units. For custom technical components, we can accommodate smaller pilot runs starting at 500 units.
Our engineering team provides quick quality validation and material specification consulting for your specific project.
Get a detailed manufacturing timeline and bulk pricing within 24 hours.
Phone Support: +1 (802) 3409134
Email Support: [email protected]
Expert perspectives on the global fastener and metal markets.

Industrial manufacturers face persistent supply chain disruptions—reliable, compliant custom industrial fasteners are critical for resilience. FastenersB2B delivers high-quality solutions with technical expertise; request a consultation to strengthen your supply chain today.
Strengthen your global supply chain with FastenersB2B’s custom industrial fasteners, technical sourcing, and quality assurance. Get compliant, durable solutions tailored to your project—contact our team today for a consultation.
Combat global supply chain volatility with engineered industrial fasteners from FastenersB2B. Access custom solutions, EN 10204 3.1 compliance, reliable lead times, and technical sourcing to strengthen manufacturing resilience.