S-90044A257 6-40 x 1 1/2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior thread precision with Class 3A fit provides tight, secure fastening with minimal backlash, ideal for precision assemblies requiring exact alignment.
• Enhanced corrosion resistance from the black-oxide finish prolongs service life in humid or chemically aggressive environments, lowering maintenance frequency.
• High hardness rating (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated installation and removal cycles.
• Optimized drive engagement with a 7/64" hex socket allows for high torque application without stripping, speeding up assembly and disassembly processes.
• Fine UNF threads deliver improved vibration resistance and better load distribution compared to coarse threads, enhancing joint stability in dynamic equipment.
• Regulatory compliance with ASTM A574, RoHS 3, and REACH ensures material consistency and environmental safety, simplifying procurement for regulated industries.

Professional Applications & Engineering Value

These 6-40 UNF thread socket head cap screws are engineered to address critical challenges in precision machinery, automotive, and aerospace assemblies. The black-oxide alloy steel construction combats corrosion and wear, while the Class 3A thread fit eliminates play in high-vibration environments, preventing loosening over time. With a partially threaded design and fine thread spacing, they provide superior clamping force in thin materials and tight spaces, reducing the need for additional locking components. Ideal for industrial fasteners requiring consistent performance, these screws ensure reliable connections in equipment where failure is not an option, supported by their high tensile strength and compliance with major standards.

Specification Summary & Compliance

This product adheres to Class 3A thread fit tolerances for precise engagement, manufactured under ASTM A574 specifications for alloy steel socket head cap screws. It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring environmental and safety standards. Threads follow UNF (Unified National Fine) standards with a right-hand direction, and dimensions are in the inch system, including a 1-1/2" length and 7/64" hex drive size.