S-91900A546 1/4"-20 x 1 1/2" ASME B18.3 Tamper-Resistant Torx Stainless Steel Button Head Screws

Key Features & Benefits at a Glance

• Tamper-resistant T27 Torx drive prevents unauthorized removal, enhancing security in public or controlled-access environments.
• 18-8 Stainless Steel construction with passivated finish provides excellent corrosion resistance, ensuring long-term reliability in harsh or outdoor conditions.
• 70,000 psi tensile strength and Rockwell B70 hardness deliver high mechanical durability and resistance to stripping or shear forces.
• Class 3A thread fit with UNC coarse threading ensures precise, secure fastening with reduced risk of cross-threading in industrial assemblies.
• Fully threaded 1-1/2" length offers consistent holding power along the entire shank for robust connections.
• Rounded button head design combines a low-profile appearance with smooth edges, minimizing snagging and improving safety.
• Compliance with ASME B18.3, RoHS 3, and REACH guarantees adherence to industry standards and environmental regulations for global supply chain compatibility.

Professional Applications & Engineering Value

This tamper-resistant Torx rounded head screw is engineered to address critical needs in industrial security and durability. The 18-8 stainless steel material and passivated finish provide superior resistance to rust and chemical exposure, making it ideal for outdoor equipment, marine hardware, or chemical processing facilities. The T27 drive style deters tampering in public infrastructure, such as utility enclosures, transportation systems, and access panels, while the Class 3A UNC coarse threads ensure quick, reliable installation with high vibration resistance. By integrating ASME B18.3 standards, this fastener delivers consistent performance in heavy-duty applications, reducing maintenance costs and enhancing operational safety where unauthorized access or environmental degradation are concerns.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with Class 3A fit for precise tolerance, a fully threaded 1-1/2" length, and a rounded button head with 0.437" diameter. It meets ASME B18.3 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free of hazardous substances and suitable for international industrial use.