S-98093A558 M8 x 40 mm ASME B18.2.3.9M, SAE J1199 High-Strength Metric Class 10.9 Steel Flanged Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength with Class 10.9 rating (150,000 PSI) ensures reliable performance in high-stress industrial environments
• Superior corrosion resistance from black-phosphate steel coating extends service life in demanding conditions
• Optimized load distribution through the 18mm flange design prevents surface damage and improves joint integrity
• Precision threading with Class 6g fit and coarse 1.25mm pitch enables faster installation and secure fastening
• Versatile partial threading with 22mm thread length provides both gripping strength and clearance where needed
• External hex drive compatibility allows for standard tooling and efficient installation in confined spaces
• Rockwell C32 hardness maintains structural integrity under repeated loading and vibration

Professional Applications & Engineering Value

This M8 hex head screw delivers exceptional engineering value through its Class 10.9 high-strength steel construction and black-phosphate surface treatment. The combination addresses critical industrial challenges including vibration-induced loosening, corrosion in harsh environments, and the need for reliable fastening under heavy loads. The partially threaded design with coarse metric threading (1.25mm pitch) ensures rapid assembly while maintaining superior clamping force. The integrated flange eliminates the need for separate washers, distributing load evenly and preventing surface damage in heavy-duty applications such as machinery assembly, structural frameworks, and automotive components. This external hex drive screw provides engineers with a comprehensive solution that balances installation efficiency with long-term performance reliability.

Specification Summary & Compliance

Manufactured to precise metric dimensions including M8 thread size, 1.25mm coarse pitch, and Class 6g thread tolerance for consistent fit. The fastener meets ASME B18.2.3.9M specifications for dimensional accuracy and performance standards. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across various industrial sectors. The 40mm length with 22mm minimum thread length and 18mm flange diameter provides standardized compatibility with industrial equipment and components.