S-91035A640 1/4"-20 x 1 1/4" ASTM A581, ASTM A582 Captive Panel Screws

Key Features & Benefits at a Glance

• Enhanced manual operation with knurled round head for superior grip without tools
• Corrosion-resistant performance in demanding environments using 18-8 stainless steel construction
• Secure panel retention through partially threaded design preventing complete disassembly
• Reliable coarse threading with UNC 1/4"-20 pattern for quick installation and vibration resistance
• Precision Class 2A thread fit ensuring consistent engagement and reduced cross-threading risks
• Dual drive compatibility featuring both thumb-operated knurl and slotted screwdriver options
• Regulatory compliance meeting ASTM A581, RoHS 3, and REACH environmental standards

Professional Applications & Engineering Value

This 18-8 stainless steel thumb screw delivers exceptional value in panel mounting and electronic enclosure applications where frequent access is required. The knurled head texture provides positive grip even with gloved hands, while the partially threaded captive design prevents lost hardware in multi-panel assemblies. Engineered with UNC coarse threading and Class 2A fit, it ensures rapid installation and reliable performance in vibration-prone environments. The corrosion-resistant properties of 18-8 stainless steel make it ideal for industrial settings, telecommunications equipment, and outdoor applications where durability is critical.

Specification Summary & Compliance

This captive panel screw features precise 1/4"-20 UNC coarse threads with Class 2A tolerance for consistent fit. The partially threaded design extends 5/16" with right-hand direction. Manufacturing complies with ASTM A581 specification for quality assurance. The product is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental and safety standards for industrial components.