S-90277A108 4-40 x 3/8" ASME B18.6.3 Steel Binding Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction for extended service life in demanding industrial environments
• Enhanced holding power through coarse UNC threading and Class 2A fit ensures secure fastening in various materials
• High tensile strength rating of 60,000 psi provides reliable performance under significant mechanical stress
• Optimized drive engagement with slotted drive design allows for straightforward installation and removal
• Wide binding head profile distributes clamping force effectively while preventing surface damage
• Full threading along 3/8" length maximizes thread engagement for stronger connections
• Consistent hardness (Rockwell B69) maintains structural integrity through repeated use cycles

Professional Applications & Engineering Value

These 4-40 UNC zinc-plated steel rounded head screws deliver exceptional engineering value across industrial applications where vibration resistance and reliable fastening are critical. The binding head design with wide profile provides superior bearing surface, preventing pull-through in softer materials while the coarse thread spacing ensures rapid installation and excellent holding power in plastics, sheet metal, and electronic enclosures. The zinc-plated finish creates a protective barrier against oxidation and corrosion, making these slotted drive screws ideal for assembly lines, electrical components, and machinery where environmental factors threaten fastener integrity. With full threading along the entire 3/8" length, these fasteners maximize engagement depth for secure connections that withstand operational stresses.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit tolerance for consistent performance across applications. These right-hand threaded screws comply with ASME B18.6.3 specifications for slotted head fasteners and meet critical regulatory requirements including RoHS 3 (2015/863/EU) compliance for restricted substances and REACH (EC 1907/2006) standards for chemical safety. The inch system measurements ensure compatibility with North American equipment and designs, while the fully threaded 4-40 UNC coarse thread configuration provides reliable fastening in accordance with industrial threading standards.