S-91286A242 3/8"-16 x 8" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 150,000 psi ensures reliable performance in the most demanding heavy-duty applications, reducing the risk of fastener failure.
• Superior corrosion resistance provided by the zinc-flake coating extends the service life of the screw, even in harsh industrial environments.
• High hardness rating (Rockwell C33) offers excellent wear resistance and durability, maintaining fastener integrity under repeated stress.
• Precise Class 2A thread fit with coarse UNC threading allows for easier, faster assembly and secure fastening in a variety of materials.
• Partially threaded design provides optimal clamping force where needed, ideal for applications requiring a non-threaded shank section.
• External hex drive and hex head design enables high-torque installation with standard tools, simplifying maintenance and assembly processes.
• Compliance with major industry standards including ASME B18.2.1 and SAE J429 ensures consistent quality and interchangeability in professional applications.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address critical challenges in heavy-duty industrial applications where joint integrity is paramount. The steel construction combined with Rockwell C33 hardness provides exceptional resistance to shear and tensile forces, preventing deformation under load. The zinc-flake coated finish offers superior protection against corrosion, making these partially threaded screws ideal for outdoor equipment, machinery assembly, and structural frameworks exposed to environmental elements. The 3/8"-16 UNC coarse thread configuration ensures rapid installation and reliable grip in both metal and composite materials, while the external hex drive accommodates high-torque applications without stripping. These features collectively deliver a high-strength fastening solution that maintains clamping force in vibrating environments, reducing maintenance frequency and downtime.

Specification Summary & Compliance

This fastener features Class 2A thread fit tolerance for consistent engagement, 3/8"-16 UNC coarse threads per ASME standards, and partial threading with minimum 1¼" thread length. Manufacturing complies with ASME B18.2.1 and SAE J429 specifications for Grade 8 fasteners. The product is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting current environmental and safety regulations for industrial use.