Discover our primary selection of high-grade industrial fasteners, brackets, and customized components designed for challenging structural applications.
In high-stress industrial applications, the choice of fastener grades is critical to structural integrity, safety, and operational longevity. High-quality grade bolts are not merely pieces of threaded metal; they are highly engineered components designed to withstand specific levels of tensile strength, yield strength, shear fatigue, and environmental corrosion.
Bolt classifications, defined by international bodies like the International Organization for Standardization (ISO) and the American Society for Testing and Materials (ASTM), represent distinct physical properties. For example, Grade 8.8, 10.9, and 12.9 (commonly defined under ISO 898-1) indicate the nominal tensile strength and the ratio between yield strength and tensile strength. A Grade 10.9 bolt features a nominal tensile strength of 1000 MPa and a yield strength value of 90% of that figure (900 MPa).
At Ningbo Krui Hardware Product Co., Ltd., we balance material chemistry with specialized heat treatments to meet these parameters consistently. Selecting the appropriate alloy, controlling temperature ramp times during hardening, and executing precision tempering ensure the microstructural properties of the steel prevent hydrogen embrittlement and premature stress fractures.
We manufacture fasteners compliant with international specifications including Metric (DIN/ISO) and Imperial (ANSI/ASME) standards. Our processes support grades from low carbon steel utility fasteners to high-strength tempered structural bolts.
Our material sourcing includes grades of Carbon Steel, Medium Carbon Alloy Steel (for Grade 8.8 and 10.9), Chrome-Moly Alloys (for Grade 12.9), and corrosion-resistant Stainless Steel grades (SUS304, SUS316, and SUS316L).
To withstand extreme environments, we offer diverse surface finishes: Zinc plating (blue, yellow, black), Hot-Dip Galvanizing (HDG), Geomet, Dacromet, and Black Oxide treatments.
Founded in 2004, Ningbo Krui Hardware Product Co., Ltd. has established itself as an experienced manufacturer in the precision hardware and structural fastener industry. Strategically located in Ningbo, one of China’s premier industrial and logistics hubs, our facility sits just 15 minutes away from the Ningbo seaport. This geographical advantage enables efficient logistics, container optimization, and reduced shipping times to global ports.
Our commitment to manufacturing quality is demonstrated by our ISO 9001:2008 quality management certification. We maintain a dedicated R&D department, a compliance-focused quality testing team, and a specialized workforce of 55 professionals. By leveraging specialized machinery and inspection tools, we ensure our production runs meet engineering tolerance specifications.
While 60–70% of our capacity serves domestic industrial demands in China, 30–40% is exported to regions including North America, South America, Europe, Australia, Japan, and South Korea. We offer both standard components (maintaining stock of 304/316(L) stainless steel fasteners) and custom OEM/ODM services to produce parts based on customer drawings or physical samples.
We manufacture fastening solutions tailored to the strict engineering requirements of key global industries.
Designed for integrated casting and concrete reinforcement, ensuring high pull-out resistance in structural applications.
Dual-threaded hardware engineered to connect wood structures to steel components, ideal for modern architectural projects.
Self-lubricating and high-load capacity bushings machined to minimize friction in rotating machinery and heavy linkages.
Industrial purchasing managers face various supply chain challenges, including volatile raw material pricing, inconsistent quality, and shipping delays. Ningbo Krui helps mitigate these risks through several key operational strategies:
A visual tour of our manufacturing facility in Ningbo, featuring processes from initial cold forging to final packaging.
How Ningbo Krui integrates material science and manufacturing processes to meet changing engineering requirements.
Modern engineering designs demand smaller, lighter assemblies without sacrificing structural safety. This shift has driven the adoption of high-strength fasteners, particularly Grade 10.9 and 12.9 alloy steels. In highly corrosive environments like offshore wind farms or marine chemical plants, standard finishes are often insufficient.
Ningbo Krui's R&D is focused on applying advanced protective coatings, such as zinc-flake and mechanical galvanizing. These coatings provide excellent salt-spray test hours while preventing hydrogen embrittlement. Hydrogen embrittlement is a common cause of failure in high-strength bolts that occurs during standard acid-pickling and electroplating processes.
Additionally, we work closely with clients to develop non-standard components, utilizing CAD modeling and prototype sampling to ensure performance prior to full-scale production runs.
Technical answers regarding fastener grades, manufacturing specifications, quality assurance, and global supply logistics.
Review our secondary selection of specialized fasteners, custom bushings, and high-tensile hardware designed for complex industrial applications.
Krui Hardware