S-91770A870 5/16"-18 x 1 3/4" ASME B18.6.3 Stainless Steel Truss Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction, ideal for harsh industrial environments
• Enhanced load distribution from the wide rounded truss head design, reducing surface damage and material stress
• High tensile strength of 70,000 psi ensures reliable performance under heavy mechanical loads
• Excellent thread engagement with Class 2A fit and coarse UNC threading for quick assembly and vibration resistance
• Optimized drive efficiency using Phillips No. 4 drive for secure torque application and reduced cam-out risk
• Partial threading design allows for precise clamping force control in various material thicknesses
• Full regulatory compliance with ASME B18.6.3, RoHS 3, and REACH standards for guaranteed quality and safety

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these 5/16"-18 UNC rounded truss head screws deliver exceptional value in assembly operations where corrosion resistance and structural integrity are paramount. The passivated 18-8 stainless steel construction provides superior protection against chemical exposure and atmospheric corrosion, making them ideal for outdoor equipment, marine hardware, and food processing machinery. The unique truss head profile offers a larger bearing surface than standard round heads, distributing clamp load effectively across softer materials or thin sheet metal while preventing pull-through. With partial threading and coarse UNC threads, these fasteners maintain secure connections in vibrating environments while allowing for adjustment in assembly depth. The combination of 70,000 psi tensile strength and Rockwell B70 hardness ensures these screws withstand high stress applications without deformation or failure, providing long-term reliability in structural frameworks, conveyor systems, and heavy machinery assemblies.

Specification Summary & Compliance

These rounded truss head screws feature precise Class 2A thread fit tolerances with 5/16"-18 UNC coarse threading and partial threading up to 1½" minimum thread length. Manufacturing complies with ASME B18.6.3 standards for dimensional accuracy and performance. The fasteners are fully compliant with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations for chemical safety, ensuring environmental responsibility and workplace safety compliance.