S-94173A313 5/16"-18 x 4" 12-Point Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress industrial applications
• Superior corrosion resistance from black-oxide alloy steel coating extends service life in demanding environments
• External 12-point drive design provides secure tool engagement and prevents stripping during high-torque installation
• Class 2A thread fit guarantees consistent assembly with standard mating components
• Integrated flange feature eliminates the need for separate washers, reducing assembly time and component count
• Rockwell C38 hardness rating maintains structural integrity under repeated loading and vibration
• Coarse UNC threading enables faster installation and superior resistance to loosening in heavy machinery

Professional Applications & Engineering Value

This high-strength 12-point screw addresses critical engineering challenges in heavy equipment, construction machinery, and industrial assembly applications where vibration resistance and reliable fastening are paramount. The black-oxide alloy steel construction provides essential corrosion protection while maintaining the 170,000 psi tensile strength required for structural connections. The external 12-point drive system ensures positive torque transmission without cam-out, making it ideal for confined spaces where socket clearance is limited. The partially threaded design with UNC coarse threading offers optimal clamping force distribution, while the integrated flange provides increased bearing surface for improved joint stability in automotive, agricultural, and manufacturing equipment applications.

Specification Summary & Compliance

This 5/16"-18 UNC 12-point screw features Class 2A thread fit per ASME B1.1 standards, ensuring dimensional accuracy and interchangeability. The 4" length with 1" minimum thread length provides versatile fastening capability. Manufactured from alloy steel with black-oxide surface treatment for enhanced durability. The product complies with industry standards for heavy-duty fasteners and meets applicable material and performance specifications for industrial applications requiring 170,000 psi tensile strength and Rockwell C38 hardness ratings.