S-94173A321 5/16"-24 x 4 1/2" 12-Point Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with black-oxide coating for extended service life in harsh industrial environments
• Superior torque transmission through the external 12-point drive design, preventing tool slippage during high-torque applications
• Precision thread engagement with Class 2A UNF fine threads ensuring reliable fastening in critical assemblies
• Enhanced load distribution from the integrated flange, reducing surface pressure and preventing material damage
• High-strength performance with 170,000 PSI tensile strength and Rockwell C38 hardness for demanding structural applications
• Optimized thread design with partial threading providing improved stress distribution along the shank
• Industry-standard compatibility with UNF fine thread specifications for seamless integration into existing systems

Professional Applications & Engineering Value

This black-oxide alloy steel 12-point screw delivers exceptional engineering value in heavy-duty applications where vibration resistance and structural integrity are paramount. The combination of 170,000 PSI tensile strength and Rockwell C38 hardness ensures reliable performance in high-stress environments such as industrial machinery, automotive assemblies, and construction equipment. The external 12-point drive provides superior torque transmission, eliminating cam-out issues common in hex drives, while the integrated flange design distributes clamping force evenly, preventing surface damage to connected materials. The UNF fine thread spacing and Class 2A thread fit guarantee precise engagement in critical applications where vibration loosening must be minimized. This partially threaded configuration optimizes stress distribution, making it ideal for applications requiring both clamping force and shear strength.

Specification Summary & Compliance

This 12-point flange screw features precise Class 2A thread fit with 5/16"-24 UNF fine thread specifications, ensuring dimensional accuracy per industry standards. The manufacturing process adheres to strict quality controls for thread diameter (0.3125") and thread spacing consistency. The black-oxide surface treatment provides corrosion protection while maintaining dimensional stability. Compliant with relevant industrial standards for alloy steel fasteners, this product meets performance requirements for high-strength applications while maintaining compatibility with standard external 12-point drive tools and industry-accepted installation practices.