S-91271A593 5/16"-18 x 2 1/2" IFI 115 12-Point Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under extreme loads and vibrations
• Precision Class 3A thread fit provides superior engagement and reduced risk of cross-threading in critical assemblies
• Integrated flange design eliminates the need for separate washers, saving installation time and reducing component count
• Alloy steel construction with Rockwell C37 hardness delivers outstanding wear resistance and durability in harsh environments
• External 12-point drive system allows for high-torque application with standard wrenches while minimizing head rounding
• Partial threading configuration optimizes clamp load distribution and prevents joint loosening in dynamic applications
• UNC coarse threading enables rapid installation and superior performance in materials requiring coarse pitch fasteners

Professional Applications & Engineering Value

This 12-point flanged screw delivers critical engineering advantages where vibration resistance and structural integrity are paramount. The alloy steel composition, combined with Rockwell C37 hardness, provides exceptional resistance to shear forces and environmental degradation in heavy machinery, construction equipment, and automotive assemblies. The flanged design distributes bearing stress over a wider surface area, preventing surface damage and maintaining joint integrity. With its 5/16"-18 UNC coarse threading and Class 3A fit, this fastener ensures precise alignment and reliable performance in high-vibration applications where partial threading prevents unwanted loosening. The external 12-point drive accommodates standard industrial wrenches while maximizing torque transmission efficiency.

Specification Summary & Compliance

Manufactured to exacting inch system dimensions with Class 3A thread fit tolerance for precision assembly. Complies with IFI 115 manufacturing specifications and maintains full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Thread specifications include 5/16"-18 UNC coarse thread with right-hand direction and 0.3125" thread diameter. Mechanical properties verified to 170,000 psi tensile strength and Rockwell C37 hardness standards.