S-94288A118 1/4"-20 x 1 1/4" Extreme-Strength Stainless Steel Flanged Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 450 stainless steel construction, ideal for harsh industrial environments and outdoor applications.
• Superior tensile strength of 170,000 psi ensures reliable performance under heavy loads, reducing the risk of fastener failure.
• Flanged design eliminates the need for separate washers, speeding up assembly and providing a larger bearing surface for better load distribution.
• Class 2A thread fit with UNC coarse threading offers easier, faster assembly and better resistance to vibration loosening in most materials.
• Rockwell C38 hardness provides excellent wear resistance and durability, extending the screw's service life in demanding applications.
• External hex drive with 5/16" head width allows for high-torque installation using standard tools, ensuring secure fastening.
• Partially threaded shank provides unthreaded grip length for precise clamping force control in structural connections.

Professional Applications & Engineering Value

This 1/4"-20 UNC hex head screw delivers critical engineering advantages for industrial applications where vibration resistance, corrosion protection, and high strength are paramount. The 450 stainless steel material provides excellent durability in corrosive environments, while the flanged design simplifies assembly by integrating washer functionality. The coarse UNC threading ensures reliable performance in softer materials and resists vibration-induced loosening better than fine threads. With partial threading, this fastener offers precise clamping control for machinery, structural frameworks, and heavy equipment where accurate load distribution is essential. The combination of 170,000 psi tensile strength and Rockwell C38 hardness makes it suitable for high-stress applications in manufacturing, construction, and automotive industries.

Specification Summary & Compliance

This 1/4"-20 UNC hex head screw features precise Class 2A thread fit tolerances per ASME/ANSI standards, ensuring consistent performance and interchangeability. The coarse thread spacing and right-hand thread direction comply with Unified National Coarse specifications. Manufacturing follows industry standards for dimensional accuracy, with 1-1/4" length and 1" minimum thread length providing reliable fastening capability. The 450 stainless steel composition meets corrosion resistance requirements, while the mechanical properties including 170,000 psi tensile strength and Rockwell C38 hardness validate performance for demanding industrial applications.