S-91253A548 1/4"-20 x 1 3/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 PSI ensures reliable performance in high-stress industrial applications
• Superior corrosion resistance from black-oxide coating extends service life in demanding environments
• Precision Class 3A thread fit guarantees secure fastening with minimal vibration loosening
• Optimized hex drive design (5/32") provides superior torque transmission and installation efficiency
• 82° countersink angle creates flush mounting for clean, professional finishes
• Partial threading configuration allows for precise clamping force control in assembled components
• Rockwell C39 hardness rating maintains structural integrity under repeated loading conditions

Professional Applications & Engineering Value

These black-oxide alloy steel flat head screws deliver critical engineering solutions where high tensile strength and corrosion resistance are paramount. The UNC coarse threading with Class 3A fit ensures rapid installation and vibration resistance in heavy machinery, automotive assemblies, and structural frameworks. The partially threaded design concentrates clamping force precisely where needed, while the 82° countersink enables seamless integration into precision-machined components. Engineered to withstand extreme mechanical stresses, these hex drive screws provide reliable fastening in manufacturing equipment, industrial enclosures, and transportation systems where failure is not an option.

Specification Summary & Compliance

Manufactured to exacting ASME B18.3 and ASTM F835 specifications with Class 3A thread fit for superior dimensional accuracy. Features 1/4"-20 UNC coarse threads with right-hand direction and 1 3/4" length. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets.