Grade 10.9 12.9 8.8 A2 70 Carbon Steel Hexagonal Socket Screw

Grade 10.9, 12.9, and 8.8 hexagonal socket screws are high-performance fasteners engineered for applications demanding precise load distribution and resistance to shear or tensile stress. The numerical grades indicate tensile strength: 10.9 and 12.9 represent high-strength alloy steels, with 12.9 offering the highest hardness for extreme mechanical loads, while 8.8 serves as a versatile medium-strength option for general industrial use. The hexagonal socket design (Allen drive) allows efficient torque application in tight spaces, reducing slippage risk. Carbon steel variants, often heat-treated, prioritize durability and cost-effectiveness in non-corrosive environments. These screws are staples in automotive suspensions, heavy machinery, and structural assemblies where failure tolerance is near-zero.

A2-70 stainless steel hexagonal socket screws cater to environments requiring corrosion resistance, such as marine hardware or chemical processing equipment. The "A2" denotes austenitic stainless steel (304 equivalent), while "70" specifies a minimum tensile strength of 700 MPa. Unlike carbon steel, A2-70 resists oxidation without coatings, making it ideal for outdoor or moisture-prone settings. However, it trades some ultimate strength for this anti-corrosive property compared to grades like 12.9. Engineers often select this material when balancing longevity against moderate mechanical stress—common in food-grade machinery, architectural fixtures, or HVAC systems. Both carbon and A2-70 variants share the hex socket’s installation precision but diverge in material trade-offs tailored to project-specific demands.