8.8 Socket head bolt
Material: 35CrMo alloy steel / 45# carbon steel
Strength Grade: 8.8
Surface Treatment: Blackening, Electro-galvanizing (optional)
Thread Specifications: M6 M8 M10 M12 M16 M20 M24 (Regular stock, all sizes conforming to DIN912)
Testing Standards: Tensile strength, yield strength, hardness, and thread precision all meet DIN912 and national standards.
Product Description
8.8 Socket head bolts are the mainstream high-strength fasteners used in the assembly of industrial equipment, mould manufacturing and mechanical engineering.
8.8 Socket head bolts offer key advantages such as high strength, high toughness, resistance to tensile stress and vibration, and resistance to stripping and breakage. They are ideally suited for fastening applications in all types of medium and heavy-duty machinery, replacing standard low-carbon steel bolts and effectively resolving issues such as loosening, breakage and rusting during long-term operation.
Product advantages
Our factory’s 8.8 grade hex socket head cap screws are manufactured without any compromise on quality or the use of inferior materials. We maintain strict quality control throughout the entire production process, from raw materials to finished products, ensuring that every single screw is a genuine, standard-compliant 8.8 grade high-strength fastener.
- Selection of high-quality raw materials: We exclusively use GB 45# medium-carbon steel, which features uniform density and excellent toughness. This ensures the product’s mechanical properties from the outset, eliminating issues such as soft threads and brittle fractures.
- Precision forming process: Utilising fully automated cold heading and thread rolling equipment for integrated forming, our screws feature high thread precision, full-profile threads and tight engagement. They offer smooth installation without slipping and excellent compatibility.
- Professional quenching and tempering heat treatment: We operate our own independent heat treatment production line. All products undergo quenching and high-temperature tempering, meeting Grade 8.8 mechanical standards. Their hardness, toughness, load-bearing capacity and fatigue resistance far exceed those of standard bolts.
- Comprehensive batch quality control: We implement a five-stage quality inspection process comprising raw material sampling, in-process inspection during forming, heat treatment hardness testing, finished product tensile testing, and 100% inspection prior to dispatch.
Applications
The 8.8 socket head bolt is widely used in various industrial manufacturing and engineering assembly applications, and is a key fastener that major enterprises procure on a long-term basis.
Our Advantages
Ample Stock Across All Sizes
We maintain a vast inventory of standard sizes from M3 to M48, with standard lengths available for immediate dispatch. We also offer customisation for extended lengths, extra-short lengths, special pitch, and non-standard hex socket bolts; we can produce these to order using custom moulds to meet specific construction requirements.
One-Stop Supply Service
Our factory can produce matching 8.8-grade nuts, flat washers and spring washers of the same specifications. The entire set features consistent quality and precision, eliminating the need for multiple suppliers and significantly reducing procurement coordination costs and material compatibility risks.
Direct from the Factory
With our own production facilities and a full suite of automated equipment, there are no mark-ups from intermediaries. We offer significant price advantages for bulk purchases, and long-term partnerships ensure stable delivery times and preferential unit prices. We support sample requests, small-batch trial orders and large-scale bulk procurement.