S-91290A121 M3 x 18 mm DIN 912, ISO 4762 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional strength-to-weight ratio with Class 12.9 rating and 170,000 psi tensile strength for reliable performance in demanding applications
• Superior corrosion resistance through black-oxide surface treatment, extending service life in harsh industrial environments
• Precision torque transmission enabled by 2.5mm hex socket drive, preventing tool slippage and ensuring secure fastening
• Optimized thread engagement with M3 coarse threading (0.5mm pitch) for faster assembly and reduced cross-threading risks
• Consistent dimensional accuracy maintained through full compliance with DIN 912/ISO 4762 manufacturing standards
• Enhanced durability from Rockwell C37 hardness, resisting wear and deformation under heavy loads
• Environmental compliance assurance meeting RoHS 3 and REACH regulations for safe use across global markets

Professional Applications & Engineering Value

These high-strength socket head cap screws solve critical fastening challenges in precision engineering applications where space constraints and vibration resistance are paramount. The black-oxide alloy steel construction provides superior corrosion protection while maintaining the Class 12.9 mechanical properties essential for heavy-duty machinery, automotive assemblies, and industrial equipment. The M3 metric thread with 0.5mm coarse pitch ensures rapid installation in blind holes and materials with varying hardness. The fully threaded design offers maximum grip length for distributed load bearing, while the 2.5mm hex drive enables high-torque application in confined spaces. These precision fasteners deliver reliable performance in robotics, CNC machinery, and automation systems where fastener failure is not an option.

Specification Summary & Compliance

Manufactured to DIN 912/ISO 4762 specifications with Class 5g6g thread fit tolerance ensuring precise mating with standard nuts and threaded components. The 18mm length and 5.5mm head diameter maintain dimensional consistency across production batches. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming absence of restricted substances. The right-hand thread direction and standard socket head profile provide compatibility with common industrial tools and assembly processes.