S-91257A562 1/4"-20 x 6" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum Load-Bearing Capacity - Grade 8 classification and 150,000 psi tensile strength ensure reliable performance in high-stress industrial applications
• Superior Corrosion Protection - Zinc yellow-chromate plating provides excellent resistance against rust and environmental degradation
• Enhanced Durability - Rockwell C33 hardness rating maintains structural integrity under repeated stress and vibration
• Optimized Thread Engagement - UNC coarse threading with Class 2A fit ensures secure fastening and easier installation in various materials
• Versatile Partial Threading - 3/4" minimum thread length allows for precise clamping force control in diverse assembly scenarios
• Industry-Standard Compliance - Meets ASME B18.2.1 and SAE J429 specifications for guaranteed interchangeability and performance
• Environmental Responsibility - RoHS 3 and REACH compliance ensures safe use in regulated industries and applications

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these Grade 8 hex head screws address critical challenges in construction, machinery assembly, and structural framing where high tensile strength and vibration resistance are paramount. The zinc yellow-chromate plating provides superior corrosion protection in harsh environments, extending service life while maintaining electrical conductivity for grounding applications. The external hex drive design allows for high-torque installation with standard tools, and the 1/4"-20 UNC coarse threads ensure rapid assembly with reduced cross-threading risk. Partially threaded construction enables precise clamping force distribution, making these steel fasteners ideal for applications requiring both shear strength and tension control.

Specification Summary & Compliance

This 6-inch hex head screw features precise Class 2A thread fit with UNC coarse threading (1/4"-20) and partial threading with minimum 3/4" thread length. Manufactured to ASME B18.2.1 and SAE J429 standards, ensuring dimensional accuracy and mechanical properties. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making them suitable for use in regulated industries and international markets.