Product Overview
Our Grade 8.8 Bolts are high-strength fasteners made to ISO 898-1 standards from premium carbon steel with a black oxide finish. These bolts meet Grade 8.8 strength (tensile strength ≥800MPa) and come in full-thread and partial-thread designs for varied connection needs. The black oxide coating offers rust protection and a clean look.As dependable Stainless Steel Hex Bolts and Hex Bolts, they are ideal for mechanical equipment, engineering structures, and heavy-duty uses. Sourced directly from a reliable China factory, our bolts deliver quality and value.We export to multiple regions including the Middle East, Southeast Asia, Africa, and Central Asia, providing consistent quality and on-time delivery for global industrial customers.
Technical Specifications
| Execution Standard | ISO 898-1 |
| Material | Medium Carbon Steel (C 0.25-0.55%) |
| Surface Treatment | Black Oxide |
| Strength Grade | Grade 8.8 (Tensile Strength ≥800MPa) |
| Thread Specification | Metric Thread (M6-M24) |
| Head Type | Hex Head (Standard Across Flats) |
| Mechanical Properties | Hardness HRC22-32 |
| Corrosion Resistance | 24-hour Salt Spray Test |
| Available Sizes | Metric: M6×12–M24×50 (various lengths) Imperial: 1/4″×0.47″–15/16″×1.97″ (various lengths) |
Application Scenarios
These Grade 8.8 High-Strength Bolts are widely used across Southeast Asia in critical applications requiring superior strength and reliability:
Heavy Machinery
Essential for secure assembly of machines that require high load capacity and vibration resistance in industrial environments
Automotive Industry
Used in vehicle manufacturing and repair for critical parts including engine components, chassis, and suspension systems
Construction Projects
Fastening steel structures, bridges, and frameworks requiring high tensile strength and structural integrity
Industrial Equipment
Suitable for equipment requiring strong, durable bolts in manufacturing plants and processing facilities
Infrastructure Projects
Used in tunnels, railways, power plants, and other critical infrastructure requiring long-term reliability
Frequently Asked Questions
What does Grade 8.8 mean?
Grade 8.8 bolts have high tensile strength of 800 MPa minimum, making them suitable for demanding structural and mechanical applications. The first digit (8) represents tensile strength in hundreds of MPa, while the second digit (8) indicates the yield strength ratio.
How does black oxide treatment help?
Black oxide provides mild corrosion resistance and a smooth, professional surface finish. It reduces friction during installation and offers better appearance compared to plain steel, while being cost-effective for indoor and dry environments.
Can I order custom lengths?
Yes, we offer various standard sizes from M6×12 to M24×50, and can customize lengths to fit your specific project requirements. Contact our technical team for custom sizing options and minimum order quantities.
Are these bolts compatible with standard nuts?
Yes, they fit standard metric nuts designed for Grade 8.8 bolts. We recommend using matching Grade 8 nuts to ensure optimal performance and safety in high-stress applications.
What’s the difference between full-thread and partial-thread bolts?
Full-thread bolts have threads along the entire length, providing maximum holding power. Partial-thread bolts have a smooth shank section, offering better shear strength and are ideal for applications where the bolt passes through clearance holes.
Our Manufacturing Facility and Products
Direct Supply from Chinese Factory
Welcome to Handan Quanfan Metal Products Co., Ltd., a leading China manufacturer specializing in fasteners including self drilling screws, drywall screws, stainless steel bolts, self tapping screws, and grade 5 nuts.
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Need more information about our Grade 8.8 High-Strength Bolts or have special requirements? We have proudly served numerous customers worldwide, including key markets in the Middle East, Southeast Asia, and Africa, delivering expert fastener solutions tailored to their needs.
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