S-91253A630 3/8"-16 x 1 3/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength: Withstands up to 130,000 PSI, ensuring reliable performance in high-stress industrial applications and reducing the risk of fastener failure.
• Superior Thread Precision: Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening in dynamic environments.
• Enhanced Durability & Corrosion Resistance: Black-oxide coating on alloy steel offers improved wear resistance and protection against rust, extending service life in harsh conditions.
• Optimized Drive Efficiency: Hex drive (7/32") allows for high-torque installation with standard tools, speeding up assembly while reducing stripping risks.
• Flush Mounting Capability: Standard flat head with 82° countersink angle enables seamless, low-profile installations for cleaner finishes and reduced snagging.
• Full Thread Engagement: Fully threaded design ensures maximum grip along the entire length, enhancing load distribution and joint integrity.
• High Hardness Rating: Rockwell C39 hardness provides excellent resistance to deformation under heavy loads, maintaining fastener shape and function over time.

Professional Applications & Engineering Value

These 3/8"-16 UNC flat head hex screws are engineered to address critical challenges in industrial assembly, where vibration, high tensile loads, and environmental exposure are common. The black-oxide alloy steel construction, combined with a Class 3A thread fit, ensures precise, secure fastening in machinery, automotive frames, and structural components, minimizing the need for frequent retightening. The coarse thread spacing and fully threaded design enhance grip in both soft and hard materials, while the 82° countersink angle allows for flush mounting in pre-drilled holes, reducing protrusion risks. Ideal for heavy-duty applications, these screws deliver consistent performance in construction, manufacturing, and equipment maintenance, where reliability and compliance with industry standards are paramount.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including UNC thread type with Class 3A thread fit for superior accuracy. It meets ASME B18.3 and ASTM F835 specifications, ensuring consistent manufacturing quality. Additionally, it is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally safe and regulated industrial use.