S-91746A244 8-40 x 3/4" Thumb Screws

Key Features & Benefits at a Glance

• Enhanced manual grip with a fully knurled round head for secure, tool-free installation and removal, even in tight spaces.
• Superior corrosion resistance provided by 18-8 Stainless Steel, ensuring long-term reliability in harsh or humid environments.
• Exceptional mechanical strength with an 80,000 psi tensile strength and Rockwell B83 hardness for high-load applications.
• Precise and secure threading featuring an 8-40 extra fine UNS thread with a Class 2A fit for vibration resistance and reliable fastening.
• Optimized for space-constrained assemblies due to its narrow profile round head and fully threaded 3/4" length.
• Compliance with major environmental regulations including RoHS 3 and REACH, making it suitable for global markets and sensitive applications.
• Right-hand thread direction for intuitive, standard manual tightening in a wide range of industrial settings.

Professional Applications & Engineering Value

This 18-8 Stainless Steel Thumb Screw is engineered to solve critical challenges in manual fastening applications where tools are impractical or access is limited. The knurled round head provides a non-slip surface, enabling secure hand-tightening and preventing loosening from vibrations, a common issue in machinery and electronic enclosures. Its extra fine 8-40 UNS thread offers a higher number of threads per inch, resulting in finer adjustment control and a stronger hold in thin materials or delicate components. The narrow profile is ideal for panels and devices with minimal clearance. Combined with the inherent corrosion resistance of stainless steel, this screw delivers long-term durability in demanding environments such as marine equipment, medical devices, and outdoor telecommunications hardware, reducing maintenance needs and replacement costs.

Specification Summary & Compliance

This thumb screw adheres to precise dimensional and performance standards. The threading conforms to UNS specifications with an 8-40 extra fine pitch and a Class 2A thread fit, ensuring consistent interchangeability and reliable performance. The product is manufactured to meet RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, confirming it is free of restricted hazardous substances. Key dimensions include a 0.164" thread diameter and a 3/4" fully threaded length.