S-90303A145 5/16"-18 x 1" ASME B18.3, ASTM A574 Nylon-Tip Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength – With 180,000 psi tensile strength, this screw withstands extreme loads and vibrations, ensuring reliable performance in demanding applications.
• Non-Marring Nylon Tip – Protects delicate surfaces from scratches and damage during installation, ideal for finished assemblies and sensitive materials.
• High Hardness & Durability – Rockwell C39 hardness provides excellent wear resistance and long service life under repetitive use.
• Wide Temperature Tolerance – Nylon tip operates from -50° to 250°F, maintaining integrity in both low and high-temperature environments.
• Precise Thread Fit – Class 3A UNC coarse threads ensure tight, secure fastening with reduced risk of cross-threading.
• Corrosion-Resistant Finish – Black-oxide coating on alloy steel enhances corrosion resistance, suitable for industrial and outdoor settings.
• Standard Socket Head Design – 1/4" hex drive allows for easy installation with common tools, improving assembly efficiency.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw with a non-marring nylon tip is engineered to solve critical fastening challenges in precision assemblies. The UNC coarse thread and Class 3A fit provide superior holding power and vibration resistance, making it ideal for machinery, automotive, and electronics where thread reliability is paramount. The protective nylon tip prevents surface damage on delicate components like anodized aluminum or painted panels, reducing rework and warranty claims. Its high tensile strength and temperature-stable tip ensure consistent performance in environments ranging from freezing cold to moderate heat, offering a durable solution for industrial fastening without compromising surface integrity.

Specification Summary & Compliance

This screw meets ASME B18.3 and ASTM A574 specifications, ensuring dimensional accuracy and manufacturing consistency. Threads are UNC coarse with a Class 3A fit for precise engagement. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming it is free from hazardous substances and suitable for global supply chains.