S-91997A224 1/4"-20 x 5/8" ASME B18.3 Sealing Tamper-Resistant Torx Stainless Steel Button Head Screws

Key Features & Benefits at a Glance

• Superior Sealing Performance: Integrated Buna-N rubber O-ring ensures reliable sealing against fluids and gases, withstanding pressures up to 1500 psi for leak-free operations in demanding environments.
• Exceptional Corrosion Resistance: Crafted from 18-8 stainless steel with a passivated finish, offering excellent durability against rust and chemical exposure, ideal for harsh industrial settings.
• Enhanced Tamper Resistance: T27 tamper-resistant Torx drive provides added security against unauthorized removal, maintaining system integrity in public or high-risk applications.
• Precision Thread Fit: Class 3A thread fit with UNC coarse threading ensures tight, reliable fastening with reduced risk of cross-threading and improved assembly efficiency.
• Wide Temperature Tolerance: O-ring functions effectively from -40° to 225°F, making it suitable for applications exposed to extreme thermal variations without compromising seal integrity.
• High Tensile Strength: With a tensile strength of 70,000 psi, this screw delivers robust mechanical performance under high-stress conditions, ensuring long-term fastener reliability.
• Regulatory Compliance: Meets ASME B18.3 specifications and is RoHS 3 and REACH compliant, providing assurance of quality and environmental safety for global industrial use.

Professional Applications & Engineering Value

This 1/4"-20 x 5/8" rounded head screw is engineered to address critical sealing and security challenges in industrial assemblies. The combination of 18-8 stainless steel and a passivated finish ensures resistance to corrosion, while the Buna-N rubber O-ring creates an effective seal against high-pressure fluids, preventing leaks in hydraulic systems, machinery enclosures, and fluid handling equipment. The T27 tamper-resistant Torx drive adds a layer of security, deterring tampering in public infrastructure, automotive components, and electronic housings. Its UNC coarse thread and Class 3A fit facilitate quick, precise installation, reducing assembly time and minimizing the risk of thread damage. Ideal for applications requiring reliable performance under pressures up to 1500 psi and temperatures from -40° to 225°F, this screw offers a dependable solution for maintaining system integrity in demanding environments like manufacturing, aerospace, and outdoor equipment.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with Class 3A thread fit for precise dimensional accuracy and secure fastening. It is manufactured in compliance with ASME B18.3 standards, ensuring consistent quality and performance. The product is RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, meeting stringent environmental and safety regulations for industrial use.