S-90179A537 1/4"-20 x 1/2" Thumb Screws

Key Features & Benefits at a Glance

• Quick manual installation and removal with the easy-grip spade head design, reducing assembly time and eliminating the need for tools.
• Enhanced durability and load distribution from the integrated flange, which acts as a built-in washer to prevent surface damage and loosening under vibration.
• Reliable thread engagement and interchangeability due to the standardized UNC coarse thread and Class 2A fit, ensuring consistent performance in various applications.
• Superior mechanical strength with a 40,000 psi tensile strength and Rockwell B55 hardness, providing excellent resistance to wear and deformation in demanding environments.
• Secure and robust fastening from the fully threaded right-hand design, offering maximum grip length for a strong hold.
• Compliance with environmental and safety standards as it is RoHS 3 Compliant, making it suitable for use in regulated industries.
• Corrosion resistance and long service life from the high-quality steel material, ideal for industrial and outdoor applications.

Professional Applications & Engineering Value

This 1/4"-20 UNC Spade Thumb Screw is engineered to address common challenges in industrial assembly, such as the need for rapid, tool-free maintenance and secure fastening under dynamic loads. The steel construction with Rockwell B55 hardness ensures it withstands repetitive use and harsh conditions without stripping or failing. Its coarse thread spacing and Class 2A thread fit facilitate quick alignment and reduce cross-threading risks, making it ideal for applications in machinery panels, electronic enclosures, and automotive components where vibration resistance is critical. The flanged design distributes clamping force evenly, minimizing damage to soft materials and enhancing joint integrity. This thumb screw is a reliable choice for engineers seeking efficiency, durability, and compliance in heavy-duty thumb screw applications.

Specification Summary & Compliance

This product adheres to UNC thread standards with a Class 2A thread fit for consistent dimensional accuracy and interchangeability. Key specifications include a thread size of 1/4"-20, fully threaded coarse spacing, and a flange diameter of 0.438". It is manufactured from high-strength steel, achieving a tensile strength of 40,000 psi and hardness of Rockwell B55. Compliance includes RoHS 3 (2015/863/EU), ensuring it meets environmental regulations for hazardous substance restrictions.