S-90409A185 5/8"-18 x 1 1/2" IFI 111, SAE J429 High-Strength Grade 8 Steel Flanged Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional Load-Bearing Capacity: With a tensile strength of 150,000 psi, this screw reliably handles extreme stress and vibration in demanding applications.
• Superior Durability and Wear Resistance: The Rockwell C32 hardness ensures the screw maintains its integrity and resists deformation under heavy loads.
• Integrated Flange for Secure Fastening: Eliminates the need for a separate washer, providing a larger bearing surface to prevent loosening and surface damage.
• Precision Fine Threading for Vibration Resistance: The 5/8"-18 UNF fine thread with a Class 2A fit offers superior holding power and resistance to vibrational loosening.
• High-Strength Material for Critical Applications: Made from Grade 8 steel, it is engineered for high-stress environments requiring maximum reliability.
• Broad Regulatory Compliance: Meets SAE J429, RoHS 3, and REACH standards, ensuring material safety and suitability for regulated industries.
• Full Threading for Maximum Grip: The fully threaded design provides consistent clamping force along the entire length of the screw.

Professional Applications & Engineering Value

This Grade 8 steel hex head screw is engineered to solve critical fastening challenges in heavy machinery, construction, and automotive assemblies. Its high tensile strength and Rockwell C32 hardness directly address the need for components that can withstand intense dynamic loads and shock without failing. The integrated flange simplifies assembly by combining the screw and washer functions, reducing part count and potential points of failure. The 5/8"-18 UNF fine thread provides a tighter, more secure fit than coarse threads, making it ideal for applications prone to vibration. Manufactured to SAE J429 specifications, it delivers the predictable performance and reliability required in industrial fastening solutions where safety and durability are non-negotiable.

Specification Summary & Compliance

This fastener features a 5/8"-18 UNF thread with a Class 2A fit for precise, consistent engagement. It is manufactured in compliance with the IFI 111 / SAE J429 specification for Grade 8 fasteners. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free of restricted hazardous substances and suitable for use in environmentally conscious and regulated markets.