S-92949A120 4-40 x 1 1/2" ASME B18.3 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh industrial environments
• Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for reliable load-bearing performance
• Precision thread engagement through Class 3A thread fit and UNC coarse threading, ensuring secure fastening in demanding applications
• Easy installation and removal with 1/16" hex drive design, reducing assembly time and tool wear
• Full-threaded length versatility across the entire 1-1/2" span, providing consistent holding power in various material thicknesses
• Rounded button head profile offers a low-profile, snag-free finish while distributing clamping force effectively
• Regulatory compliance assurance meeting ASME B18.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

These 4-40 UNC threaded rounded head screws deliver critical performance in industrial settings where vibration resistance, corrosion protection, and consistent clamping force are paramount. The 18-8 stainless steel composition combined with passivated surface treatment creates a durable barrier against chemical exposure and atmospheric corrosion, extending service life in manufacturing equipment, electronic enclosures, and machinery assemblies. The coarse UNC threading and Class 3A thread fit provide superior engagement in both metallic and non-metallic materials, reducing the risk of cross-threading during high-volume production. The hex drive configuration ensures positive torque transmission without cam-out, while the rounded button head design minimizes protrusion in confined spaces. These fasteners solve common engineering challenges including galvanic corrosion, thread stripping, and installation efficiency across automotive, aerospace, and industrial automation applications.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 3A thread tolerances and UNC coarse thread form, these screws maintain consistent threading accuracy. The 1-1/2" length and fully threaded design provide uniform engagement throughout the fastener. Compliance includes ASME B18.3 dimensional specifications, RoHS 3 (2015/863/EU) restriction of hazardous substances, and REACH (EC 1907/2006) chemical safety standards, ensuring environmental responsibility and regulatory adherence for global industrial applications.