Big OD Washer (Big Outer Diameter Washer) is a type of washer that has a larger outer diameter (OD) compared to standard washers, while still maintaining a smaller central hole for the fastener. The increased outer diameter helps distribute the load over a larger surface area, reducing the risk of damage to the material being fastened. ... This makes it ideal for applications that require enhanced load distribution and stability, especially when using softer or more delicate materials. Big OD washers are commonly used in heavy-duty applications such as construction, machinery, and automotive industries, where securing fasteners with maximum support is crucial. They are typically made from materials like steel, stainless steel, or aluminum, offering durability and corrosion resistance.