S-90287A839 4-40 x 1/2" Tamper-Resistant One-Way-Drive Steel Round Head Screws

Key Features & Benefits at a Glance

• Exceptional holding power with 60,000 psi tensile strength for reliable performance in demanding applications
• Superior corrosion resistance provided by zinc-plated steel, extending service life in industrial environments
• Easy installation and removal with standard rounded head design and one-way drive style
• Optimal thread engagement through fully threaded UNC coarse threads for maximum grip strength
• Precise fit and compatibility ensured by Class 2A thread fit for consistent assembly quality
• Broad industrial applicability with right-hand threading conforming to inch system standards
• Environmental compliance assurance meeting RoHS 3 and REACH regulations for sustainable manufacturing

Professional Applications & Engineering Value

These 4-40 UNC zinc-plated steel rounded head screws deliver exceptional engineering value across multiple industrial sectors. The combination of 60,000 psi tensile strength and fully threaded coarse UNC threads provides superior resistance to vibration loosening and mechanical stress, making them ideal for assembly lines, machinery components, and electronic enclosures. The zinc-plated steel construction offers excellent corrosion protection in environments where moisture or chemical exposure is a concern, while the rounded head profile ensures smooth surface contact and reduced stress concentration. These industrial screws solve critical fastening challenges by maintaining structural integrity under load while complying with international environmental standards for manufacturing operations requiring reliable, long-lasting fastening solutions.

Specification Summary & Compliance

This fastener features precise Class 2A thread fit with UNC coarse threads (4-40 size) in right-hand thread direction, manufactured to inch system specifications. The 1/2" length and fully threaded design ensure consistent performance across applications. Compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming environmental safety standards for industrial use. The combination of dimensional accuracy and material properties provides reliable fastening performance while meeting international regulatory requirements for hazardous substance restrictions.