High-tensile fasteners are the backbone of the heavy engineering, automotive, and construction sectors. SRG Fasteners specializes in the production of high-strength bolts and nuts in property classes 8.8, 10.9, and 12.9.
Our manufacturing process involves precision cold-forging or hot-forging followed by advanced heat treatment in controlled-atmosphere furnaces. This ensures that every high-tensile bolt achieves the exact balance of hardness, tensile strength, and ductility specified by international standards.
From bridge skeletons and skyscraper foundations to heavy machinery and engine components, our high-tensile hardware provides the reliable clamping force needed to endure extreme loads and vibrations over long service lives.
What is the difference between Grade 8.8 and 10.9?
Grade 10.9 bolts have a higher tensile strength (1040 MPa) and yield strength compared to Grade 8.8 (800 MPa), making them suitable for more critical load-bearing applications.
Which coating is best for high-tensile bolts?
Zinc plating or Hot Dip Galvanizing (HDG) are common. However, for extreme strength (12.9), we often recommend Phosphating or specialized coatings to avoid hydrogen embrittlement.