S-91571A436 7/8"-9 x 3 3/4" ASME B18.2.6, ASTM A325, ASTM F3125 Medium-Strength Steel Heavy Hex Head Screws for Structural Applications
Medium-Strength Steel Heavy Hex Head Screws for Structural Applications
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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 structural applications, reducing the risk of fastener failure.
- Superior grip length of 2 1/4" provides enhanced clamping force and stability in critical connections, minimizing joint movement.
- Partially threaded design allows for precise load distribution and prevents thread damage in shear-critical assemblies.
- Class 2A thread fit with coarse UNC threading enables quick installation and easy alignment, saving time during assembly.
- High hardness (Rockwell C19) offers excellent wear resistance and durability, extending service life in demanding environments.
- External hex drive facilitates straightforward installation and removal with standard tools, improving maintenance efficiency.
- Compliance with major standards including ASME B18.2.6, ASTM A325, and ASTM F3125 ensures consistent quality and reliability for structural projects.
Professional Applications & Engineering Value
This Grade A325 heavy-duty hex head screw is engineered to address critical challenges in structural steel connections, where vibration, dynamic loads, and environmental factors can compromise integrity. The partially threaded design concentrates stress away from the threaded section, enhancing fatigue resistance in structural applications like bridges, building frames, and heavy machinery. Made from high-strength steel and featuring a coarse UNC thread, it resists loosening under cyclic loading while the external hex drive allows for high-torque installation. This combination of material strength and precise thread spacing ensures long-term reliability, reducing maintenance needs and downtime in industrial and construction settings.
Specification Summary & Compliance
This screw adheres to precise dimensional standards with a Class 2A thread fit and UNC coarse thread for consistent engagement. It meets ASME B18.2.6, ASTM A325, and ASTM F3125 specifications, ensuring manufacturing consistency and performance. Environmental compliance is confirmed with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) adherence, supporting sustainable procurement practices.
