S-91247A020 1/4"-28 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
- High tensile strength of 120,000 psi ensures reliable performance in demanding applications, reducing the risk of fastener failure.
- Zinc plating provides excellent corrosion resistance, extending service life in various industrial environments.
- Grade 5 classification and Rockwell C25 hardness offer superior durability and consistent mechanical properties.
- UNF fine thread with Class 2A fit allows for precise engagement and vibration resistance in critical assemblies.
- Partially threaded design enables secure clamping where full threading is not required, improving installation efficiency.
- External hex drive and hex head facilitate easy installation and removal with standard tools, reducing assembly time.
- Compliance with ASME B18.2.1, RoHS 3, and REACH ensures adherence to industry standards and environmental regulations for safe use.
Professional Applications & Engineering Value
This Grade 5 hex head screw is engineered to address common industrial challenges such as joint integrity and environmental exposure. Made from zinc plated steel, it combats corrosion in machinery, automotive, and construction applications where moisture or chemicals are present. The 1/4"-28 UNF fine thread and Class 2A thread fit provide tight, secure fastening that resists loosening under vibration, making it ideal for equipment subjected to dynamic loads. With a partially threaded shank and external hex drive, it simplifies assembly in confined spaces, reducing labor costs and enhancing reliability in heavy-duty frameworks. These features ensure long-term performance in structural supports, engine components, and industrial assemblies, minimizing maintenance downtime.
Specification Summary & Compliance
This fastener features precise Class 2A thread fit and adheres to UNF fine thread standards with a thread size of 1/4"-28. It meets ASME B18.2.1 and SAE J429 specifications for dimensional accuracy and mechanical properties. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it ensures environmental safety and regulatory adherence in global supply chains.
