S-99926A151 5/16"-18 x 1 1/2" Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ensuring longevity in harsh industrial environments.
• High tensile strength of 70,000 psi provides reliable fastening under heavy loads, reducing the risk of mechanical failure.
• Class 3A thread fit ensures precise, tight engagement with mating parts for vibration-resistant assemblies.
• Undercut flat head with 100° countersink angle allows for flush mounting, minimizing protrusion and improving aesthetic finish.
• Hex drive (5/32") design offers secure tool engagement, enabling efficient installation and removal with standard tools.
• Partially threaded coarse (UNC) design facilitates easier alignment and faster assembly in a variety of materials.
• Compliance with RoHS 3 and REACH standards guarantees environmental safety and regulatory acceptance for global supply chains.

Professional Applications & Engineering Value

These 5/16"-18 UNC flat head screws are engineered to address common industrial fastening challenges, such as corrosion in moist or chemical-exposed settings. The 18-8 stainless steel material combined with a passivated finish enhances durability, while the Rockwell B70 hardness ensures the screw maintains integrity under repetitive stress. The undercut flat head profile and 100° countersink angle enable seamless integration into countersunk holes, preventing surface damage and providing a smooth finish—ideal for applications in machinery, automotive assemblies, and structural frameworks where reliable fastening and aesthetic considerations are critical. The coarse thread and partial threading further support quick, secure installations in wood, metal, and composite materials.

Specification Summary & Compliance

This screw adheres to UNC coarse thread standards with a Class 3A thread fit for high precision. Dimensions include a thread size of 5/16"-18, length of 1-1/2", and minimum thread length of 1.32". It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring it is free of hazardous substances and suitable for regulated industrial applications.