S-91236A553 1/4"-20 x 2 3/4" ASME B18.2.1, ASTM A307 Low-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Enhanced corrosion resistance with zinc plating for extended service life in demanding environments
• Superior tensile strength rated at 60,000 psi for reliable, heavy-duty fastening applications
• High material hardness (Rockwell B69) provides excellent wear resistance and durability
• Coarse UNC threading ensures quick assembly and reduced cross-threading risk
• External hex drive design allows for high-torque installation with common tools
• Partial threading offers optimal grip length for secure connections in various material thicknesses
• Precision Class 2A thread fit guarantees consistent performance and interchangeability

Professional Applications & Engineering Value

These 1/4"-20 UNC hex head screws deliver exceptional engineering value in industrial settings where vibration resistance and structural integrity are paramount. The zinc plated steel construction provides essential corrosion protection for machinery, equipment frames, and structural assemblies exposed to harsh conditions. The coarse thread design prevents loosening under dynamic loads, while the external hex drive enables efficient installation in confined spaces. With partial threading optimizing clamp load distribution, these fasteners solve critical challenges in manufacturing, construction, and heavy equipment applications requiring reliable fastening solutions that withstand rigorous operational demands.

Specification Summary & Compliance

Manufactured to ASME B18.2.1 specifications with Class 2A thread fit tolerance for precision performance. These 1/4"-20 UNC hex head screws feature a 2-3/4" length with minimum 3/4" thread engagement. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting ASTM A307 grade requirements for commercial steel fasteners.