S-91251A022 1/2"-20 x 2 1/2" ASTM A574 Alloy Steel Socket Head Screws
Alloy Steel Socket 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 170,000 psi for reliable performance in high-stress and heavy-duty applications.
- Superior corrosion resistance provided by the black-oxide finish, extending service life in harsh industrial environments.
- Precision Class 3A thread fit ensures tight, secure fastening with minimal risk of loosening under vibration.
- High hardness (Rockwell C37) offers excellent wear resistance and durability for repeated use.
- Fine UNF thread design allows for finer adjustments and improved clamping force in precision assemblies.
- Partially threaded shank provides unthreaded bearing surface for better alignment and stress distribution.
- Compliance with ASTM A574, RoHS 3, and REACH guarantees material quality and environmental safety for global supply chains.
Professional Applications & Engineering Value
This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in demanding sectors such as machinery, automotive, and heavy equipment. The 1/2"-20 UNF fine thread and Class 3A precision fit deliver superior clamping force and vibration resistance, reducing maintenance needs in dynamic environments. Its high tensile strength (170,000 psi) and Rockwell C37 hardness ensure it withstands extreme loads and wear, while the black-oxide surface treatment enhances corrosion resistance, making it ideal for applications exposed to moisture, chemicals, or outdoor conditions. The hex drive (3/8") allows for easy installation in confined spaces, supporting efficient assembly in complex industrial setups.
Specification Summary & Compliance
This screw features a 1/2"-20 UNF fine thread with Class 3A thread fit for high precision, a length of 2 1/2", and a partially threaded design. It complies with ASTM A574 specifications for alloy steel socket head cap screws, ensuring consistent manufacturing quality. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting strict environmental and safety standards for industrial use.
