S-91251A106 4-40 x 1/4" ASTM A574 Alloy Steel Socket Head Screws
Alloy Steel Socket Head Screws
Image may differ from product. See technical specification for details.
Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
- Fast delivery
- Enjoy discounts on bulk purchases
- Secure Payment
- Fast Global Shipping
Key Features & Benefits at a Glance
- Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
- Superior corrosion resistance from the black-oxide finish extends service life in harsh or humid industrial environments.
- Precision Class 3A thread fit provides secure, tight fastening with minimal backlash, enhancing assembly accuracy.
- High hardness (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
- Standard hex socket drive allows for easy installation with common tools, speeding up assembly and maintenance processes.
- Full threading along the 1/4" length ensures maximum grip and adjustability in various material thicknesses.
- Compliance with ASTM A574, RoHS 3, and REACH guarantees material quality and environmental safety for global supply chains.
Professional Applications & Engineering Value
This 4-40 UNC socket head cap screw is engineered to address critical challenges in precision machinery, automotive, and electronics assembly. The black-oxide alloy steel construction combats corrosion and wear, while the coarse UNC threads and Class 3A fit provide robust, vibration-resistant connections in metals and plastics. Its high tensile strength and fully threaded design ensure consistent clamping force, reducing loosening in dynamic loads. Ideal for compact spaces, the 3/32" hex drive facilitates secure tool engagement, streamlining maintenance in confined industrial setups without compromising on durability or regulatory compliance.
Specification Summary & Compliance
This fastener features a 4-40 UNC coarse thread with Class 3A tolerance for precise fit, a 1/4" length, and right-hand thread direction. Manufactured to ASTM A574 specifications, it ensures consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting safe and sustainable industrial use.
