S-91783A539 1/4"-20 x 5/8" ASME B18.6.3 Stainless Steel Round Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance thanks to 18-8 stainless steel construction and passivated finish, ideal for harsh environments
• High tensile strength of 100,000 psi ensures reliable performance in demanding industrial applications
• Excellent thread engagement with Class 2A UNC coarse threads for faster assembly and reduced cross-threading risk
• Durable rounded head design provides a finished appearance and reduces surface snagging
• Full threading along the 5/8" length offers maximum grip and uniform load distribution
• Wide regulatory compliance including ASME B18.6.3, RoHS 3, and REACH for global supply chain compatibility
• Rockwell B100 hardness maintains structural integrity under repeated stress and vibration

Professional Applications & Engineering Value

This 1/4"-20 UNC coarse thread screw is engineered to address common industrial challenges such as corrosion-induced failure and assembly inefficiency. The 18-8 stainless steel material combined with a passivated finish provides exceptional resistance to oxidation and chemical exposure, making it suitable for outdoor equipment, marine hardware, and food processing machinery. The rounded head slotted design allows for straightforward installation with standard tools while minimizing protrusion in compact assemblies. With a 100,000 psi tensile strength and fully threaded shank, it ensures secure fastening in high-vibration environments like automotive subassemblies and industrial conveyors, reducing maintenance downtime and improving operational reliability.

Specification Summary & Compliance

This screw adheres to Class 2A thread fit per UNC standards, ensuring precise dimensional accuracy and interchangeability. Manufacturing and quality are governed by ASME B18.6.3 specifications, while environmental and safety compliance is confirmed through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations. The right-hand thread direction and coarse thread spacing facilitate quick installation, and the specified Rockwell B100 hardness and 100,000 psi tensile strength validate its use in heavy-duty mechanical applications.