S-91309A585 5/16"-18 x 1 1/4" ASME B18.2.1, ASTM A307 Low-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating, extending service life in demanding industrial environments
• High tensile strength of 60,000 psi ensures reliable load-bearing capacity for heavy-duty applications
• Class 2A coarse UNC threads provide faster assembly and reduced cross-threading risk
• Fully threaded design offers consistent gripping power along the entire fastener length
• External hex drive enables high-torque installation with standard tools
• Rockwell B69 hardness maintains thread integrity under vibration and stress
• Full regulatory compliance meets ASME, ASTM, RoHS 3 and REACH standards for global project acceptance

Professional Applications & Engineering Value

This 5/16"-18 UNC hex head screw delivers critical engineering solutions where vibration resistance and structural integrity are paramount. The coarse thread profile prevents loosening in dynamic equipment while the zinc-plated steel construction combats corrosion in manufacturing facilities, outdoor structures, and mechanical assemblies. With 60,000 psi tensile strength and Rockwell B69 hardness, it maintains clamp load in high-stress joints where ordinary fasteners would fail. The external hex drive accommodates high installation torque for secure connections in steel framing, machinery guards, and heavy equipment maintenance applications requiring ASME B18.2.1 compliance.

Specification Summary & Compliance

Manufactured to Class 2A thread fit tolerances with UNC coarse threading (5/16"-18) and 1-1/4" length. Complies with ASME B18.2.1 dimensional standards and ASTM A307 material specifications. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for hazardous substance restrictions.