S-91286A119 1/4"-20 x 1 3/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 150,000 psi ensures reliable performance in high-stress industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance with zinc-flake coating provides long-lasting protection in harsh environments, extending service life and minimizing maintenance.
• High hardness rating (Rockwell C33) offers excellent wear resistance, maintaining thread integrity through repeated use and vibration.
• Coarse UNC threading with Class 2A fit enables quicker installation and better debris resistance in demanding conditions.
• Partially threaded design allows for precise clamping force control, ideal for applications requiring specific grip range.
• External hex drive facilitates easy installation with standard tools, reducing assembly time and labor costs.
• Grade 8 certification guarantees consistent quality and mechanical properties for critical heavy-duty applications.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these Grade 8 hex head screws deliver exceptional performance where reliability is paramount. The zinc-flake coated steel construction provides superior corrosion protection, addressing common failure points in manufacturing equipment, construction machinery, and automotive assemblies. The 1/4"-20 UNC coarse thread design ensures rapid installation and maintains holding power in vibrating environments, while the partially threaded configuration allows engineers to optimize clamp load distribution. With 150,000 psi tensile strength and Rockwell C33 hardness, these fasteners withstand extreme mechanical stresses, making them ideal for structural connections, heavy machinery, and high-vibration applications where fastener integrity cannot be compromised.

Specification Summary & Compliance

This 1/4"-20 UNC hex head screw features Class 2A thread fit for standard industrial applications, with a minimum thread length of 3/4" and overall length of 1 3/4". Manufactured to ASME B18.2.1 and SAE J429 Grade 8 specifications, ensuring dimensional accuracy and mechanical performance. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making them suitable for global industrial supply chains.