S-91257A575 1/4"-28 x 3 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws
High-Strength Grade 8 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 load-bearing capacity with a tensile strength of 150,000 psi, ideal for high-stress applications requiring reliable fastening.
- Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in harsh industrial environments.
- High hardness and durability with Rockwell C33 hardness, ensuring the screw maintains integrity under repeated use and vibration.
- Precise and secure threading with UNF fine threads and Class 2A fit, reducing the risk of cross-threading and ensuring consistent clamping force.
- Easy installation and removal thanks to the external hex head design, allowing for efficient torque application with standard tools.
- Compliance with industry standards including ASME B18.2.1 and SAE J429, guaranteeing consistent quality and interoperability in mechanical assemblies.
- Environmental and safety adherence through RoHS 3 and REACH compliance, making it suitable for regulated industries and sustainable practices.
Professional Applications & Engineering Value
This Grade 8 hex head screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery assembly, construction equipment, and automotive systems. The steel material combined with a zinc yellow-chromate finish offers robust protection against corrosion and wear, reducing maintenance downtime. Featuring a 1/4"-28 UNF thread with fine spacing and partial threading, it provides optimal grip and vibration resistance in applications where precise tension control is essential. The external hex drive ensures quick, secure fastening with common tools, enhancing productivity in time-sensitive projects while meeting rigorous ASME B18.2.1 specifications for reliability.
Specification Summary & Compliance
This fastener adheres to precise dimensional standards, including a Class 2A thread fit for consistent engagement and a 3 1/2" length with a minimum thread length of 3/4". It conforms to ASME B18.2.1 and SAE J429 specifications, ensuring mechanical integrity. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting safe and environmentally responsible usage in global markets.
