S-90313A509 0.25" ID x 1" OD Oversized Washers

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh environments and extending service life
• Excellent load distribution due to precise 1" OD and 0.25" ID dimensions, preventing surface damage and loosening
• Enhanced durability from Rockwell B68 hardness, resisting deformation under high stress and repeated use
• Reliable fit and function with compatibility for No. 12 screws, ensuring secure fastening in assemblies
• Strict environmental compliance meeting RoHS 3 and REACH standards, safe for regulated industrial applications
• Consistent performance with thickness tolerance of 0.060-0.090", providing uniform pressure and vibration resistance
• Broad industrial suitability as inch-system flat washers, versatile for machinery, equipment, and structural uses

Professional Applications & Engineering Value

These 18-8 stainless steel flat washers deliver critical engineering value by addressing common industrial challenges like corrosion-induced failure and joint instability. The stainless steel material offers inherent resistance to rust and chemicals, making them perfect for outdoor, marine, or chemical processing applications where moisture exposure is a concern. With a Rockwell B68 hardness, they maintain shape under heavy loads, reducing the risk of fastener loosening due to vibration—common in automotive or machinery assemblies. The precise 0.25" ID and 1" OD ensure optimal load spreading, protecting surfaces from galling and distributing stress evenly in No. 12 screw installations. This combination of corrosion resistance, dimensional accuracy, and mechanical strength makes these flat washers a reliable choice for engineers seeking long-term performance in demanding environments.

Specification Summary & Compliance

This flat washer adheres to inch measurement standards with an inner diameter of 0.25", outer diameter of 1", and thickness ranging from 0.060" to 0.090" for consistent fit. It is designed for use with No. 12 screw sizes and manufactured from 18-8 stainless steel with a hardness of Rockwell B68 to ensure mechanical reliability. The product fully complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free of restricted hazardous substances and safe for industrial and international supply chains.