S-90550A106 1/2"-13 x 1 1/4" ASME B18.3, ASTM F879, MIL-DTL-18240 Venting Stainless Steel Hex-Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments and long-term reliability.
• High-strength, precision threading via Class 3A UNC coarse threads ensures secure, vibration-resistant fastening and easy installation.
• Efficient installation and removal with a 5/16" hex drive, providing a positive grip and reducing tool slippage.
• Optimal flush mounting thanks to the standard flat head profile and 82° countersink angle for a clean, finished appearance.
• Prevents pressure buildup with a vented design featuring a 1/8" vent diameter, crucial for applications requiring pressure equalization.
• Full-length threading along the 1-1/4" length offers maximum grip and holding power across the entire fastener.
• Compliance with major industry standards including ASME B18.3, ASTM F879, and MIL-DTL-18240, ensuring consistent quality and performance.

Professional Applications & Engineering Value

This 1/2"-13 UNC flat head screw is engineered from 18-8 stainless steel to address common industrial challenges such as corrosion, high stress, and the need for reliable, flush-mounted fasteners. The coarse UNC threading and Class 3A thread fit provide excellent engagement in a variety of materials, reducing the risk of cross-threading and stripping. The hex drive allows for high-torque application, making it suitable for assembly lines and maintenance where speed and security are critical. Its vented feature is particularly valuable in pressurized systems or enclosures, preventing vacuum or pressure lock. Ideal for machinery, automotive assemblies, and structural applications, this screw delivers durability and performance where failure is not an option.

Specification Summary & Compliance

This screw features a 1/2"-13 UNC coarse thread with a Class 3A thread fit for precise, high-quality engagement. It is fully threaded and measures 1-1/4" in length with a head diameter of 0.938". Manufactured in compliance with ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications, ensuring it meets rigorous industrial standards. The product is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming its adherence to environmental and safety regulations for use in global markets.