S-99926A138 1/4"-20 x 3/4" Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish for extended service life in harsh environments
• Precise flush mounting enabled by undercut flat head design and 100° countersink angle for seamless industrial finishes
• High-strength fastening performance with 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Reliable thread engagement through Class 3A thread fit and UNC coarse threading for vibration resistance
• Secure installation control with 1/8" hex drive providing positive torque transmission during assembly
• Optimized weight distribution through partial threading design for balanced strength-to-weight ratio
• Environmental compliance assurance meeting RoHS 3 and REACH regulations for global manufacturing requirements

Professional Applications & Engineering Value

These 1/4"-20 UNC flat head screws deliver exceptional engineering value in industrial applications where corrosion resistance, precise flush mounting, and reliable fastening are critical. The 18-8 stainless steel construction with passivated finish provides superior protection against chemical exposure and environmental factors, making them ideal for machinery, electrical enclosures, and outdoor equipment. The undercut flat head profile ensures perfect countersinking without material protrusion, while the Class 3A thread fit maintains tight tolerances in vibration-prone environments. The combination of 70,000 psi tensile strength and Rockwell B70 hardness ensures these hex drive screws withstand heavy mechanical loads without stripping or failure, providing long-term reliability in manufacturing, automotive, and construction applications.

Specification Summary & Compliance

This flat head screw features precision 1/4"-20 UNC coarse threading with Class 3A thread fit for superior dimensional accuracy. Manufacturing specifications include 0.531" head diameter, 3/4" length, and partial threading with minimum 0.61" thread length. The product fully complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in global industrial markets and electronic applications.