As a leader in the fastener industry, SINSUN Hardware provides Grade 5 carriage bolts designed for heavy-duty load-bearing applications. These bolts, known for their dome-shaped heads and square shoulders, ensure self-locking stability in wood-to-wood or wood-to-metal joints.
Our Grade 5 Carriage Bolts are manufactured to meet ASTM A449/SAE J429 standards, providing a tensile strength of 120,000 PSI. In the global industrial landscape, these are critical for infrastructure, agricultural machinery, and heavy framing. By leveraging our 30,000 sqm production facility, we maintain consistent heat-treatment cycles, ensuring the hardening levels are perfectly calibrated for long-term vibration resistance.
Our 2025 technical strategy includes the integration of automated optical sorting and real-time salt spray analytics, achieving corrosion resistance exceeding 1,000 hours. We are moving toward "Industry 4.0" compliant manufacturing, where every batch is traceable from the raw material origin (Xing Tai Steel) to the final galvanized coating.
Whether for North American timber frame construction or South American infrastructure, our bolts adhere to international regulatory requirements. We provide full mill test reports (MTR) and ISO 9001 quality assurance documentation, ensuring compliance with local building codes across our global markets.
Grade 5 bolts are heat-treated to provide significantly higher tensile and yield strength, making them suitable for structural applications, whereas Grade 2 is for general-purpose, non-structural use.
Yes, we offer hot-dip galvanized, mechanical galvanized, and zinc-plated finishes, all optimized for specific environmental stress levels.
