S-91268A649 1/2"-13 x 4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional strength for demanding applications with Grade 8 classification and 150,000 psi tensile strength
• Superior wear resistance and durability provided by Rockwell C33 hardness and steel construction
• Reliable coarse threading with 1/2"-13 UNC thread and Class 2A fit for secure fastening in various materials
• Optimized partial threading design allowing for precise clamping force control in heavy-duty assemblies
• Easy installation and removal with external hex drive and 3/4" head width for standard tool compatibility
• Full regulatory compliance meeting ASME B18.2.1, SAE J429 standards plus RoHS 3 and REACH environmental directives
• Right-hand thread direction ensuring standard installation procedures and compatibility with existing systems

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver exceptional performance in heavy-duty industrial applications where failure is not an option. The combination of 150,000 psi tensile strength and Rockwell C33 hardness ensures reliable performance under extreme vibration and load conditions commonly encountered in construction equipment, machinery frames, and structural steel connections. The 1/2"-13 UNC coarse thread provides superior grip in both metallic and non-metallic materials, while the partially threaded design allows for precise clamping force distribution. The external hex drive with substantial 3/4" head width enables high-torque installation without stripping, making these steel fasteners ideal for critical joints requiring repeated maintenance access.

Specification Summary & Compliance

This 4" length hex head screw features 1/2"-13 UNC coarse threads with Class 2A thread fit ensuring proper clearance and engagement. Manufacturing complies with ASME B18.2.1 and SAE J429 specifications for dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, containing no substances of very high concern above threshold limits. The minimum thread length of 1 1/4" provides sufficient engaged threads for optimal load distribution in assembled applications.