S-91247A025 1/4"-28 x 3 1/4" 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
- Exceptional tensile strength of 120,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
- Zinc plating provides superior corrosion resistance, extending service life in harsh or outdoor environments.
- Grade 5 steel construction with Rockwell C25 hardness offers an optimal balance of strength and durability for demanding industrial use.
- UNF fine thread design delivers improved vibration resistance and finer adjustment capabilities compared to coarse threads.
- Class 2A thread fit ensures consistent, easy assembly while maintaining secure fastening in a wide range of materials.
- External hex drive allows for high-torque installation with standard tools, speeding up assembly and maintenance processes.
- Partially threaded shank provides unthreaded bearing surface for better clamping force distribution and joint stability.
Professional Applications & Engineering Value
These Grade 5 steel hex head screws are engineered to solve critical fastening challenges in industrial applications where vibration resistance, high tensile strength, and corrosion protection are paramount. The UNF fine thread configuration maintains clamping force under dynamic loads, making these partially threaded screws ideal for machinery, automotive assemblies, and structural frameworks. The zinc plated finish protects against environmental degradation while the external hex drive enables efficient installation in confined spaces. With their 3 1/4" length and 1/4"-28 thread size, these heavy-duty fasteners provide reliable performance in equipment requiring precise thread engagement and long-term durability.
Specification Summary & Compliance
This hex head screw features precision Class 2A thread fit with UNF fine thread specifications and manufacturing compliance with ASME B18.2.1 and SAE J429 standards. The product meets environmental regulations including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) requirements, ensuring safe use across various industrial sectors.
