S-91247A358 1/2"-20 x 2 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws
Medium-Strength Grade 5 Steel Hex Head Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Superior corrosion resistance with zinc plating for extended service life in harsh industrial environments
- High tensile strength of 120,000 psi provides reliable performance in heavy-duty applications
- Precise Class 2A thread fit ensures smooth assembly and consistent clamping force
- Grade 5 steel construction with Rockwell C25 hardness offers excellent durability and fatigue resistance
- External hex drive design allows for high-torque installation with standard tools
- Partially threaded UNF fine thread provides optimal grip strength while reducing weight
- Compliance with major standards including ASME B18.2.1 and SAE J429 guarantees quality and interchangeability
Professional Applications & Engineering Value
This Grade 5 steel hex head screw delivers exceptional engineering value across demanding industrial applications. The combination of 120,000 psi tensile strength and Rockwell C25 hardness makes it ideal for structural assemblies, machinery frames, and heavy equipment where vibration resistance and load-bearing capacity are critical. The zinc plated finish provides reliable corrosion protection in manufacturing facilities, outdoor equipment, and automotive applications. The 1/2"-20 UNF fine thread with Class 2A fit ensures precise engagement in tapped holes, reducing the risk of cross-threading while maintaining consistent preload. The partially threaded design concentrates the clamping force where needed most, making these hex head screws perfect for applications requiring both shear strength and precise joint compression.
Specification Summary & Compliance
Manufactured to exacting Class 2A thread fit tolerances with 1/2"-20 UNF fine thread specifications. This hex head screw complies with ASME B18.2.1 and SAE J429 Grade 5 standards, ensuring dimensional accuracy and mechanical properties. The fastener is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, meeting current environmental regulations for industrial use. With a minimum thread length of 1 1/4" and overall length of 2 1/2", this inch-system fastener delivers reliable performance in standardized applications.
