Bowed Spring Washers

Product Description

Bowed spring washers, often called curved spring washers, are specialized fasteners designed to act as a mechanical "spring" within an assembly. Unlike standard flat washers, they have a slight arch or "bow" that provides a predictable amount of tension (spring force) when compressed.

How They Work

Bowed washers are used to maintain tension and counteract the effects of vibration, thermal expansion, or mechanical "play." When you tighten a bolt against a bowed washer, it flattens slightly, exerting a constant upward force against the bolt head and a downward force against the substrate.

Key Industrial Uses

• Vibration Dampening: In automotive engines or industrial motors, they prevent nuts and bolts from loosening due to constant shaking.

• Thermal Expansion: They absorb the movement of metals that expand and contract as they heat up and cool down, maintaining a tight seal.

• Bearing Preload: Often used in small electric motors or precision instruments to apply a light, consistent load on ball bearings, reducing noise and wear.

• Take-up of Accumulative Tolerances: They "fill the gap" in assemblies where parts might not fit perfectly flush, ensuring there is no rattling.

Material Selection

Because these washers are functional springs, they must be made from materials that can return to their original shape after being compressed.

• Spring Steel: The most common material, offering high "memory" and strength. Usually finished with Zinc Plating or Black Oxide for basic rust protection.

• 304/316 Stainless Steel: Essential for food-grade machinery, medical devices, or marine use where rust would cause the spring to fail.

• Phosphor Bronze: Used in electrical applications because it is non-magnetic and has excellent fatigue resistance and conductivity.

Comparison: Bowed vs. Other Spring Washers

Recommended Options

uxcell 304 Stainless Bowed Washers

Made from 304 stainless steel, these are ideal for outdoor use or home appliances. They provide a smooth, consistent spring rate and won't rust when exposed to moisture.

Industrial Spring Steel Assortment

A heavy-duty kit of spring steel washers. These are heat-treated for maximum resilience, making them suitable for workshop repairs or automotive engine components.

Important Considerations

1. Deflection: Do not over-tighten a bowed washer to the point that it is 100% flat unless the application specifically calls for it. Most are designed to work best when compressed to about 50% to 80% of their height.

2. Surface Protection: Because the edges of the "bow" press into the surface, they can sometimes scratch soft materials. Using stainless steel or a polished finish can help minimize marring.

Are you using these for vibration control in a motor, or to maintain a tight seal on a door or hatch? Knowing the load requirements can help determine if a bowed washer or a wave washer is the better fit.