S-90429A158 3/8"-24 x 4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 psi for reliable performance in demanding applications
• Precision Class 3A thread fit ensures tight, secure connections and reduces the risk of loosening
• Alloy steel construction with Rockwell C39 hardness provides superior durability and wear resistance
• 82° countersink angle with standard flat head profile allows for flush mounting and improved aesthetics
• Hex drive design (7/32") enables easy installation and high torque application with standard tools
• Partial threading offers optimal grip length while minimizing unnecessary thread engagement
• Comprehensive compliance with ASTM F835, RoHS 3, and REACH standards ensures regulatory acceptance

Professional Applications & Engineering Value

These 3/8"-24 UNF flat head screws deliver critical engineering advantages for industrial assembly applications where high-strength fastening and precision alignment are paramount. The alloy steel composition, combined with Rockwell C39 hardness, provides exceptional resistance to shear forces and vibrational loosening in heavy machinery, automotive components, and structural frameworks. The fine UNF threading with Class 3A fit maintains precise tolerances in critical connections, while the 82° countersink angle ensures seamless flush mounting in predrilled surfaces. The hex drive configuration allows for efficient installation in confined spaces, making these partially threaded screws ideal for applications requiring specific grip lengths without full threading.

Specification Summary & Compliance

This 4" length flat head screw features 3/8"-24 UNF fine threading with Class 3A thread fit precision and partial threading up to 1½" minimum thread length. Manufactured to ASTM F835 specifications with 82° countersink angle and hex drive compatibility. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for industrial use.