S-91268A981 2"-4 1/2 x 9" ASME B18.2.1, ASTM A354BD High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 150,000 psi tensile strength and Grade 8 classification for reliable performance in high-stress applications
• Superior durability and wear resistance due to Rockwell C33 hardness, ensuring long service life in demanding industrial environments
• Optimized for quick assembly with coarse UNC threads and Class 2A fit, providing secure fastening while reducing installation time
• Enhanced torque application from the 3" external hex head design, allowing for high tightening forces without slippage
• Versatile partial threading (min 4½") enables precise clamping control where unthreaded shank strength is critical
• Full regulatory compliance with RoHS 3 and REACH standards, ensuring environmental safety and global market acceptance
• Guaranteed interchangeability through strict adherence to ASME B18.2.1 and ASTM A354BD specifications

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical engineering solutions for heavy machinery, structural steel connections, and industrial equipment where vibration resistance and structural integrity are paramount. The 2"-4½ UNC coarse thread configuration maintains holding power in soft materials and accelerates installation in production environments. Manufactured from high-strength steel with Rockwell C33 hardness, these fasteners withstand extreme tension and shear forces while the partial threading design prevents thread damage in clearance holes. The 3" hex head with external drive accommodates standard industrial tools for maintenance accessibility. Ideal for construction, mining, and manufacturing applications requiring ASME B18.2.1 compliant fasteners that combine maximum 150,000 psi tensile strength with corrosion-resistant properties.

Specification Summary & Compliance

Manufactured to Class 2A thread fit tolerances with 2"-4½ UNC coarse threads in right-hand direction. Meets ASME B18.2.1 dimensional standards and ASTM A354BD material specifications. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Available in inch system measurements with 9" overall length and partially threaded design (minimum 4½" thread length).