S-90313A321 0.344" ID x 2.5" OD Oversized Washers

Key Features & Benefits at a Glance

• Superior corrosion resistance from 18-8 stainless steel construction, ensuring long-term reliability in harsh or humid industrial environments.
• Precise dimensional fit with 0.344" inner diameter designed specifically for 5/16" screws, preventing loosening and improving assembly accuracy.
• Enhanced load distribution thanks to the large 2.5" outer diameter, reducing surface pressure and protecting components from damage.
• Consistent thickness tolerance between 0.051" and 0.080", providing uniform performance and ease of installation in repetitive applications.
• Full regulatory compliance with RoHS 3 and REACH standards, making it safe for use in regulated industries and international markets.
• Durable material properties of 18-8 stainless steel offer excellent strength and wear resistance without requiring additional coatings.
• Versatile inch system sizing ensures compatibility with standard US machinery and existing fastener inventories.

Professional Applications & Engineering Value

This 18-8 stainless steel flat washer is engineered to address common challenges in industrial assembly, such as corrosion-induced failure and uneven load distribution. The 2.5" OD and 0.344" ID provide an optimal balance between coverage and fit for 5/16" screw size applications, reducing stress concentrations on soft materials or painted surfaces. Made from 18-8 stainless steel, it resists oxidation and chemical exposure in demanding settings like marine equipment, food processing machinery, and outdoor structures. Its flat washer design ensures reliable performance in vibration-prone assemblies, while compliance with RoHS and REACH supports use in environmentally sensitive or regulated projects. This combination of material durability and precision sizing makes it a trusted component for maintenance, manufacturing, and heavy-duty engineering applications.

Specification Summary & Compliance

This flat washer conforms to standard inch system measurements with an inner diameter of 0.344", outer diameter of 2.5", and thickness ranging from 0.051" to 0.080". It is manufactured from 18-8 stainless steel for consistent performance and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it meets strict environmental and safety standards for industrial use.