S-91783A551 1/4"-20 x 2 1/4" ASME B18.6.3 Stainless Steel Round Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh industrial environments
• Exceptional mechanical strength delivering 100,000 psi tensile strength and Rockwell B100 hardness for reliable, long-term fastening
• Optimized thread engagement with Class 2A UNC coarse threads ensuring secure installation and vibration resistance
• Versatile partial threading allowing unthreaded shank sections for precise clamping and alignment in assembled components
• Broad compliance coverage meeting ASME B18.6.3 specifications plus RoHS 3 and REACH environmental regulations
• User-friendly installation featuring standard slotted drive and rounded head profile for straightforward tool engagement
• Right-hand thread direction providing intuitive, industry-standard installation for maintenance and production workflows

Professional Applications & Engineering Value

These 1/4-20 UNC partially threaded rounded head screws deliver critical performance where corrosion resistance and mechanical reliability are paramount. The 18-8 stainless steel base material combined with passivated surface treatment creates a protective oxide layer that significantly extends service life in moist or chemically aggressive environments. The coarse UNC thread form with Class 2A tolerance ensures rapid installation with reduced cross-threading risk, while the partially threaded design provides an unthreaded shoulder that acts as a precision pilot in assembled structures. This combination addresses common industrial challenges including vibration-induced loosening, galvanic corrosion, and assembly misalignment across machinery, electrical enclosures, and structural frameworks.

Specification Summary & Compliance

Manufactured to ASME B18.6.3 specifications with Class 2A thread fit ensuring dimensional consistency. The 1/4"-20 UNC coarse thread maintains standard engagement properties with partial threading extending 1-1/2" minimum. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations confirms environmental responsibility, while mechanical properties including 100,000 psi tensile strength and Rockwell B100 hardness validate structural performance.