S-90377A121 0.188" ID x 0.75" OD Oversized Washers

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coated 18-8 stainless steel, ideal for harsh environments and extending service life.
• Enhanced load distribution due to precise 0.75" OD and 0.188" ID, reducing surface pressure and preventing damage to assembled materials.
• Reliable hardness performance with Rockwell B68 rating, ensuring consistent durability under mechanical stress and vibration.
• Optimized thickness tolerance of 0.040-0.060" for secure fitting and uniform spacing in No. 8 screw applications.
• Compliance with global standards including RoHS 3 and REACH, guaranteeing safe use in regulated industrial sectors.
• Excellent wear resistance from the black-oxide finish, which also minimizes galling and provides a non-reflective surface.
• Broad compatibility with inch-system fasteners, simplifying sourcing and replacement in maintenance and assembly operations.

Professional Applications & Engineering Value

This black-oxide 18-8 stainless steel flat washer is engineered to address common industrial challenges such as corrosion, material fatigue, and assembly instability. The 18-8 stainless steel base offers inherent resistance to rust and chemicals, while the black-oxide surface treatment enhances protection against oxidation and wear in demanding settings like outdoor machinery, marine equipment, and chemical processing plants. With a precise inner diameter of 0.188" for No. 8 screws, it ensures accurate alignment and even load distribution, reducing the risk of loosening under dynamic loads. Its Rockwell B68 hardness provides the necessary toughness to withstand repeated stress, making it a reliable choice for automotive, construction, and electrical enclosures where long-term performance and corrosion resistance are critical.

Specification Summary & Compliance

This flat washer features an inner diameter of 0.188", outer diameter of 0.75", and thickness range of 0.040-0.060", designed for use with No. 8 screws in the inch measurement system. It conforms to standard dimensional tolerances for flat washers and is manufactured from 18-8 stainless steel with a black-oxide finish. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring adherence to environmental and safety requirements for industrial components.