S-91253A951 1/2"-20 x 4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws
Alloy Steel Hex Drive Flat 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
- Superior tensile strength – 130,000 psi rating ensures reliable performance in high-stress industrial applications.
- Precision Class 3A thread fit – Delivers tight, secure fastening with minimal risk of loosening under vibration.
- Durable alloy steel construction – With Rockwell C39 hardness for excellent wear and deformation resistance.
- 82° countersink angle – Allows for flush mounting, reducing snagging and improving aesthetics in assembled products.
- 5/16" hex drive – Provides positive torque transmission and easy installation with standard tools.
- Partial threading design – Offers optimal grip length while reducing weight and material usage.
- Compliance with ASTM F835, RoHS 3, and REACH – Ensures material safety and meets rigorous industrial standards.
Professional Applications & Engineering Value
This 1/2"-20 UNF flat head screw is engineered to address critical fastening challenges in heavy machinery, automotive assemblies, and structural frameworks. The alloy steel composition, combined with Rockwell C39 hardness, provides exceptional resistance to shear and tensile forces, preventing premature failure in dynamic environments. The Class 3A thread fit and fine thread spacing ensure vibration-resistant connections, reducing maintenance needs. Its 82° countersink angle and hex drive facilitate quick, flush installations in countersunk holes, ideal for applications where surface smoothness and aerodynamic profiles are essential. These features make it a trusted choice for industrial fasteners requiring high reliability and compliance with ASTM F835 specifications.
Specification Summary & Compliance
This screw adheres to Class 3A thread fit per UNF standards, ensuring precise dimensional accuracy and interchangeability. It meets ASTM F835 specifications for mechanical properties and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted hazardous substances. The manufacturing process guarantees consistent thread diameter and length tolerances, supporting reliable performance in regulated industrial applications.
