S-90086A685 1/4"-20 x 1 1/4" ASME B18.6.3, SAE J933 Tapping Screws

Key Features & Benefits at a Glance

• Superior thread cutting performance in aluminum, brass, cast iron, and sheet metal without pre-tapped holes, reducing installation time and labor costs.
• Enhanced corrosion resistance from the Black-Oxide Steel finish, ensuring long-term durability in various industrial environments.
• Optimized 82° countersink angle allows the flat head to sit flush with the material surface, providing a clean, professional finish.
• Reliable fastening with UNC coarse threads offers excellent holding power and reduced risk of cross-threading in coarse-grained materials.
• Full 1-1/4" threading maximizes grip length and load distribution, ideal for thicker material sections.
• No. 3 Phillips drive ensures common tool compatibility and efficient torque transfer during installation.
• Compliance with ASME B18.6.3 and RoHS 3 guarantees consistent quality, safety, and environmental standards for professional use.

Professional Applications & Engineering Value

These 1/4-20 UNC coarse thread tapping screws are engineered to solve common industrial fastening challenges in aluminum, brass, cast iron, and sheet metal assemblies. The Type F thread cutting design and blunt tip enable efficient chip clearance and secure thread formation, minimizing material stress and preventing stripping. Made from Black-Oxide Steel, they resist rust and wear in demanding conditions, while the Phillips flat head with an 82° countersink ensures a smooth, flush fit that avoids protrusions. This combination delivers reliable performance in construction, metalworking, and machinery applications, enhancing assembly speed and joint integrity without the need for additional tapping operations.

Specification Summary & Compliance

This product adheres to UNC coarse thread standards with a 1/4"-20 thread size and is fully threaded for consistent engagement. It meets ASME B18.6.3 specifications (referencing SAE J933) for dimensional accuracy and performance, ensuring reliable thread cutting with a recommended No. 1 drill bit (0.228" diameter). The screws are RoHS 3 (2015/863/EU) Compliant, confirming they are free of hazardous substances, and are designed for use with standard inch measurements and right-hand threading.