S-94173A303 1/4"-20 x 4 1/2" 12-Point Screws

Key Features & Benefits at a Glance

• Exceptional strength and durability with 170,000 psi tensile strength and Rockwell C38 hardness for reliable performance in demanding applications.
• Superior corrosion resistance provided by the black-oxide finish on alloy steel, extending service life in harsh industrial environments.
• High-torque capability from the external 12-point drive and head design, allowing for secure installation with standard tools.
• Secure fastening and vibration resistance due to the integrated flange, eliminating the need for separate washers and maintaining joint integrity.
• Easy alignment and reduced cross-threading with UNC coarse threading and Class 2A thread fit, ensuring quick and accurate assembly.
• Optimized load distribution through partial threading, concentrating strength where needed most in heavy-duty connections.
• Versatile inch-system compatibility with standard 1/4"-20 thread size, making it ideal for a wide range of machinery and equipment.

Professional Applications & Engineering Value

This black-oxide alloy steel 12-point screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery assembly, construction equipment, and automotive systems. The UNC coarse thread and Class 2A thread fit provide reliable engagement, reducing the risk of stripping and ensuring consistent clamp load under vibration. The external 12-point drive offers superior torque transmission, minimizing slippage during high-stress installations. With a flanged design, it distributes pressure evenly, preventing surface damage and simplifying inventory by eliminating separate washers. The partial threading concentrates strength in the engaged section, ideal for applications requiring precise unthreaded shank areas. These features make it a top choice for engineers seeking high-strength screws that deliver long-term reliability in rigorous environments.

Specification Summary & Compliance

This screw adheres to UNC thread standards with a Class 2A thread fit, ensuring precise dimensional accuracy and interchangeability. It meets common industrial specifications for inch-system fasteners, with a thread size of 1/4"-20, coarse spacing, and a minimum thread length of 1 inch. Manufactured from alloy steel, it complies with typical material performance guidelines and is suitable for applications requiring high tensile strength and hardness. The product is designed to align with general industry practices for heavy-duty fasteners and may conform to relevant standards such as ASME for mechanical fasteners, though specific certifications should be verified per order requirements.