S-91128A121 0.688" ID Square Washers
Square Washers
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Basic Information
Dimension Parameters
Material & Strength Parameters
Installation & Application Parameters
Finish & Compliance Parameters
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Key Features & Benefits at a Glance
- Enhanced corrosion resistance through black-oxide steel coating, extending service life in humid or outdoor environments
- Superior load distribution with 3" width square design, preventing surface damage and fastener loosening under heavy loads
- Precision fit for 5/8" screws with 0.688" ID, ensuring secure fastening and reducing installation time
- Exceptional mechanical durability with Rockwell 15N80 hardness, maintaining structural integrity under repeated stress
- Reliable thickness consistency (0.235-0.265") for uniform clamping force and vibration resistance
- Full regulatory compliance with RoHS 3 and REACH standards, ensuring safe use in global industrial applications
- Optimized for inch-system assemblies, providing seamless compatibility with North American machinery and equipment
Professional Applications & Engineering Value
Engineered for demanding industrial environments, these black-oxide steel square washers solve critical challenges in heavy machinery, structural steel connections, and construction assemblies. The 3" width provides 400% more surface contact than standard washers, effectively distributing clamp load to prevent material deformation and joint failure. The Rockwell 15N80 hardness ensures the washer maintains its shape under extreme pressure, while the black-oxide finish offers superior corrosion protection without changing dimensional tolerances. Perfect for 5/8" screw applications in bridge construction, industrial equipment mounting, and structural framework where vibration resistance and long-term reliability are paramount.
Specification Summary & Compliance
Manufactured to inch system standards with precise dimensional control: 0.688" ID (±0.005"), 3" width, and thickness range of 0.235-0.265". The black-oxide steel construction meets industrial hardness requirements (Rockwell 15N80) for heavy-duty applications. Fully compliant with RoHS 3 (2015/863/EU) under exemption 6(a) for lead as steel alloying element and REACH (EC 1907/2006) regulations (updated January 17, 2023, 233 SVHC), ensuring environmental safety and global market acceptance.
