S-91781A743 4-48 x 1/2" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance thanks to 18-8 stainless steel construction and passivated finish, ideal for harsh or humid environments.
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for reliable performance under high stress.
• Precise and secure fastening ensured by the Class 2A thread fit and UNF fine thread profile, minimizing the risk of loosening.
• Flush and unobtrusive installation with the standard 82° flat head profile, perfect for applications requiring a smooth surface finish.
• Full threading for maximum grip along the entire 1/2" length, providing superior holding power in pre-tapped holes.
• Broad regulatory compliance including ASME B18.6.3, RoHS 3, and REACH, ensuring product safety and global acceptance.
• Easy manual installation and removal with the simple slotted drive style, suitable for maintenance and assembly without specialized tools.

Professional Applications & Engineering Value

These 4-48 UNF flat head slotted screws are precision-engineered from 18-8 stainless steel to address common challenges in industrial assembly, such as vibration-induced loosening and environmental degradation. The UNF fine thread and Class 2A fit provide excellent engagement in thin materials and pre-tapped holes, reducing the likelihood of cross-threading and ensuring a secure, long-lasting connection. The passivated finish significantly enhances corrosion resistance, making these flat head screws ideal for electronics, aerospace components, and machinery exposed to moisture or chemicals. Their fully threaded design and 82° countersink angle allow for a flush mount, which is critical in applications where protrusions are not permissible, improving both safety and aesthetics.

Specification Summary & Compliance

This fastener adheres to inch system measurements with a Class 2A thread fit and UNF fine thread specification (4-48 size, 1/2" length). It is manufactured in compliance with ASME B18.6.3 standards and is confirmed RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring it meets rigorous safety and environmental regulations for global industrial use.