S-91355A179 1/4"-20 x 7/8" Steel Flanged Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with black-oxide coating, extending service life in harsh industrial environments
• Superior load-bearing capacity from 120,000 psi tensile strength, preventing fastener failure under high stress
• Precise thread engagement with Class 3A UNC coarse threads, ensuring reliable assembly and vibration resistance
• Enhanced torque transmission through 5/32" hex drive design, reducing tool slippage during installation
• Increased bearing surface area with wide button head and 0.563" flange, distributing clamp force more effectively
• Consistent mechanical properties with Rockwell C32 hardness, maintaining dimensional stability under load
• Full regulatory compliance meeting RoHS 3 and REACH standards, ensuring environmental and safety requirements

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these black-oxide alloy steel screws combine high tensile strength with superior corrosion protection to address common failure points in machinery, automotive, and heavy equipment assembly. The fully threaded UNC coarse pattern with Class 3A fit ensures rapid installation and reliable performance in vibration-prone environments, while the rounded head with integrated flange eliminates the need for separate washers, streamlining assembly processes. The 5/32" hex drive provides secure tool engagement for high-torque applications, making these flanged screws ideal for critical joints requiring consistent clamp load and long-term reliability.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 3A thread fit and UNC coarse thread specifications (1/4"-20). Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Mechanical properties include Rockwell C32 hardness and 120,000 psi tensile strength, ensuring consistent performance across industrial applications.