S-91117A260 1.375" ID x 4" OD Oversized Washers

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in harsh industrial environments.
• Excellent load distribution due to the 4" outer diameter, minimizing surface damage and loosening under high stress.
• Precise fit for 1 1/4" screws with a 1.375" inner diameter, ensuring secure fastening and reducing assembly errors.
• Enhanced durability from Rockwell B40 hardness, providing reliable performance under repetitive loads and vibrations.
• Consistent thickness control between 0.485" and 0.515", offering uniform pressure and stability in applications.
• Compliance with global standards including RoHS 3 and REACH, ensuring safe and sustainable use in regulated industries.
• Heavy-duty design ideal for demanding applications, reducing maintenance needs and downtime.

Professional Applications & Engineering Value

This zinc-plated steel flat washer is engineered to address common industrial challenges such as corrosion, vibration loosening, and uneven load distribution. The inch-based dimensions, including a 1.375" ID and 4" OD, ensure compatibility with standard 1 1/4" screw sizes, making it a reliable choice for construction, machinery assembly, and heavy equipment. The zinc plating provides a protective barrier against moisture and chemicals, while the Rockwell B40 hardness enhances resistance to deformation under high-pressure conditions. Ideal for industrial washers applications, it helps prevent bolt fatigue and extends the lifespan of fastened joints, delivering consistent performance in automotive, structural, and manufacturing sectors.

Specification Summary & Compliance

This flat washer adheres to standard inch measurement tolerances, with precise inner diameter (1.375"), outer diameter (4"), and thickness range (0.485" to 0.515") for reliable fit and function. It conforms to common thread standards for 1 1/4" screws and is manufactured to ensure consistent quality. The product is RoHS 3 (2015/863/EU) compliant under exemption 6(a) for lead in steel alloys and REACH (EC 1907/2006) compliant as of January 17, 2023, meeting stringent environmental and safety regulations for industrial use.