S-90275A115 4-40 x 1" ASME B18.6.3 Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced Corrosion Resistance: Zinc-plated steel construction provides reliable protection against rust, extending service life in demanding environments.
• Superior Tensile Strength: Rated at 60,000 psi tensile strength, these screws offer exceptional load-bearing capacity for secure, long-lasting assemblies.
• Optimized Thread Engagement: Class 2A thread fit and UNC coarse threads ensure easy starting, quick installation, and reduced risk of cross-threading.
• Flush Mounting Capability: Standard flat head with an 82° countersink angle allows for a smooth, finished surface when installed.
• High Material Hardness: Rockwell B70 hardness provides excellent resistance to wear and deformation during installation and use.
• Full Threading for Maximum Grip: Fully threaded design offers consistent holding power along the entire 1" length for versatile applications.
• Broad Regulatory Compliance: Meets ASME B18.6.3 dimensional standards and is RoHS 3 & REACH compliant for safe, global use.

Professional Applications & Engineering Value

These 4-40 UNC flat head slotted screws are engineered to address common industrial fastening challenges, such as vibration loosening and material fatigue. The zinc-plated steel offers a cost-effective barrier against corrosion, making them ideal for electronics enclosures, machinery panels, and automotive components where environmental exposure is a concern. The coarse UNC thread and Class 2A fit provide excellent engagement in various materials, reducing installation time and improving reliability. The 82° countersink ensures a flush fit, preventing snagging and maintaining aerodynamic or aesthetic surfaces. Fully threaded for uniform stress distribution, these screws deliver consistent clamping force, which is critical in assemblies subject to thermal cycling or dynamic loads.

Specification Summary & Compliance

This product adheres to ASME B18.6.3 specifications for dimensional accuracy, featuring a Class 2A thread fit for consistent performance. The UNC coarse thread with right-hand direction and full threading along the 1" length ensures reliable fastening. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations confirms the absence of hazardous substances, supporting use in regulated industries.