S-91770A883 3/8"-16 x 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 through wide truss head design, reducing surface pressure and preventing material damage
• High tensile strength of 70,000 psi ensures reliable performance in demanding mechanical applications
• Excellent thread engagement with UNC coarse threading and Class 2A fit for quick installation and secure fastening
• Optimized drive efficiency featuring Phillips No. 4 drive for controlled torque application and reduced cam-out risk
• Partial threading design provides unthreaded shank strength where maximum clamping force is required
• Rockwell B70 hardness maintains structural integrity under repeated stress and vibration

Professional Applications & Engineering Value

This rounded truss head screw delivers exceptional engineering value through its passivated 18-8 stainless steel composition, specifically engineered to combat corrosion in challenging environments including marine, chemical processing, and outdoor construction applications. The wide truss head design significantly increases bearing surface area, effectively distributing clamp load across a broader surface to prevent material deformation in softer substrates like plastics or composite materials. The 3/8"-16 UNC coarse thread configuration ensures rapid installation while maintaining secure fastening in wood, metal, and plastic assemblies. With partial threading providing maximum shank strength in the unthreaded portion, this fastener excels in applications requiring precise clamp load control and vibration resistance, making it ideal for machinery assembly, structural frameworks, and heavy equipment maintenance where reliability is paramount.

Specification Summary & Compliance

Manufactured to exacting ASME B18.6.3 standards with Class 2A thread fit tolerances for consistent performance. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Features precise dimensional specifications including 4" length, 0.823" head diameter, and 1½" minimum thread length. The UNC coarse thread pattern with 3/8"-16 sizing ensures compatibility with standard industrial applications and maintains 70,000 psi tensile strength with Rockwell B70 hardness for durable performance.