S-91035A810 1/4"-28 x 1 1/2" ASTM A581, ASTM A582 Captive Panel Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel construction, ideal for harsh industrial environments and extended service life.
• Enhanced manual grip and torque application provided by the knurled, round thumb head, eliminating the need for tools in frequent access panels.
• Secure and precise thread engagement with a 1/4"-28 UNF fine thread and Class 2A fit, reducing the risk of cross-threading and ensuring reliable fastening.
• Optimized for captive panel applications due to its partially threaded design, preventing the screw from being completely removed and lost.
• Compliance with major industry and environmental standards including ASTM A581, RoHS 3, and REACH, guaranteeing material quality and regulatory safety.
• Dual drive capability with a slotted drive style, offering flexibility for tool use if required alongside manual thumb operation.
• Right-hand thread direction for intuitive, standard installation that aligns with common assembly practices.

Professional Applications & Engineering Value

This 18-8 Stainless Steel Thumb Screw is engineered to solve critical challenges in captive panel and frequent-access enclosure applications. The knurled head provides a non-slip surface, allowing operators to apply sufficient torque by hand without tools, which is essential in electronics, telecommunications, and machinery panels where quick maintenance is required. The 1/4"-28 UNF fine threading and Class 2A thread fit ensure a tight, vibration-resistant connection, minimizing loosening in dynamic environments. Made from corrosion-resistant 18-8 stainless steel, it withstands exposure to moisture, chemicals, and varying temperatures, making it a durable choice for industrial, marine, and outdoor equipment. The partially threaded shank design specifically addresses the need for secure, captive fastening, preventing the screw from falling out and getting lost during panel removal, thereby enhancing operational efficiency and reducing downtime.

Specification Summary & Compliance

This thumb screw features a 1/4"-28 UNF fine thread with a Class 2A thread fit for precise dimensional accuracy and reliable engagement. It is manufactured in compliance with ASTM A581 specifications for quality consistency. The product is also verified to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring it meets stringent environmental and safety regulations for hazardous substances.