S-91858A593 5/16"-18 x 2 1/2" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh environments and chemical exposure
• Enhanced durability and strength with 70,000 psi tensile strength and Rockwell B80 hardness for heavy-duty applications
• Reliable flush mounting thanks to the standard flat head profile and 82° countersink angle for seamless surface integration
• Easy installation and removal with slotted drive style and coarse UNC threading for quick assembly in various materials
• Precise thread engagement ensured by Class 2A thread fit, reducing cross-threading risks and improving connection integrity
• Long-lasting performance from passivated finish, which increases surface hardness and corrosion resistance
• Compliance with industry standards including ASME B18.6.3, RoHS 3, and REACH for safe, regulated use in industrial settings

Professional Applications & Engineering Value

These 5/16"-18 UNC flat head screws in 316 stainless steel are engineered to address common industrial challenges like corrosion, vibration loosening, and high-stress demands. The partially threaded design provides optimal grip in materials where full threading isn't necessary, reducing installation time and material stress. With a passivated finish, the screws offer extended service life in moist or chemically aggressive environments, such as marine equipment, food processing machinery, and outdoor structures. The coarse thread and right-hand direction ensure quick fastening in soft metals or plastics, while the flat head and standard countersink angle allow for flush mounting in countersunk holes, preventing snagging and maintaining aerodynamic or aesthetic surfaces. Ideal for applications requiring reliable, corrosion-resistant fastening that meets rigorous ASME B18.6.3 specifications.

Specification Summary & Compliance

This screw features precise Class 2A thread fit and UNC coarse threading (5/16"-18) with a minimum thread length of 1 1/2" and overall length of 2 1/2". It complies with ASME B18.6.3 manufacturing standards, ensuring dimensional accuracy and performance reliability. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming adherence to environmental and safety regulations for industrial use.