S-91997A226 1/4"-20 x 1" ASME B18.3 Sealing Tamper-Resistant Torx Stainless Steel Button Head Screws

Key Features & Benefits at a Glance

• Tamper-resistant T27 drive prevents unauthorized removal, enhancing equipment security in public or high-risk environments.
• Buna-N rubber O-ring provides reliable sealing up to 1500 psi, ideal for fluid and gas containment systems.
• 18-8 stainless steel with passivated finish offers excellent corrosion resistance for long-term durability in harsh conditions.
• Class 3A thread fit and UNC coarse threading ensure precise, secure fastening with reduced risk of cross-threading.
• Fully threaded 1" length allows for consistent clamping force across the entire engagement area.
• Wide O-ring temperature range (-40° to 225° F) maintains sealing integrity in extreme thermal environments.
• 70000 psi tensile strength delivers high mechanical reliability for demanding industrial applications.

Professional Applications & Engineering Value

This rounded head tamper-resistant Torx screw is engineered to address critical challenges in industrial assembly where both security and sealing are paramount. The combination of 18-8 stainless steel material and passivated finish provides superior resistance to corrosion, making it suitable for outdoor, marine, or chemical exposure applications. The integrated Buna-N rubber O-ring creates an effective seal against liquids and gases, preventing leaks in pressurized systems up to 1500 psi. The tamper-resistant T27 drive deters vandalism and unauthorized access, which is essential for public infrastructure, electrical enclosures, and machinery safety covers. With its UNC coarse thread and Class 3A fit, installation is quick and reliable, reducing assembly time and minimizing the risk of thread damage in high-volume production environments.

Specification Summary & Compliance

This screw features precise 1/4"-20 UNC coarse threads with Class 3A fit for accurate engagement and high tensile strength. It is manufactured in compliance with ASME B18.3 standards, ensuring dimensional consistency and performance reliability. The product is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for use in various industrial markets.