Explore the different types of washers including flat, spring, and lock washers with tips on selecting the right material and size for your project.

What Are Washers Functions and Core Benefits

Washers are small but crucial components that sit between a fastener—like a bolt or screw—and the surface being fastened. Their core role is to distribute the load of the fastener evenly, protecting the material from damage and preventing the fastener from pulling through. This simple function helps keep your connections strong and stable.

Beyond load distribution, washers offer key benefits:

• Reduce friction between fastener and surface
• Absorb shock and vibrations to protect joints
• Act as spacers to maintain proper alignment
• Seal joints against leaks or dirt
• Enhance overall joint integrity for longer-lasting assemblies

Here’s a quick stat: using washers can extend the life of fasteners by up to 50 percent when working in high-vibration environments, making them essential for durability.

Not all washers are the same. Let’s dive into the three primary categories and find the right type for your project.

The Three Main Types of Washers A Breakdown

Plain Washers Flat Washers

These are simple, flat discs that spread the load evenly across surfaces. They help prevent damage and ensure the fastener holds tight.

• Subtypes
  • Standard flat washers: The go-to for most jobs
  • Fender washers: Larger outer diameter for soft or thin materials
  • Countersunk/beveled washers: Designed for flush fits with angled screws
• Ideal uses
  • General assembly tasks
  • Woodworking projects
  • Automotive panels
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  Pair with Vast’s USS SAE flat washers for better precision in sizing.

Spring Washers

Made in helical or curved shapes, spring washers compress to keep tension on a bolt or screw, preventing it from loosening.

• Subtypes
  • Split washers: Crescent-shaped for flexible tension
  • Belleville washers: Cone-shaped and stackable, great for heavy loads
  • Wave and multi-wave washers: Best for light vibration damping
• Ideal uses
  • Machinery and engines
  • Thermal expansion situations where parts move or shift
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  Vast’s carbon steel split washers are perfect for dynamic and high-vibration jobs.

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These washers have textured or deformed surfaces that stop fasteners from coming loose due to torque or vibration.

• Subtypes
  • Internal tooth washers: Teeth grip the inside of the hole
  • External tooth washers: Teeth bite around the outside for extra grip
  • Star washers: Multi-pronged for strong resistance
  • Nylon-insert washers: Use friction from a nylon ring to lock
• Ideal uses
  • Construction
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  • High-security fixtures
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Zinc-plated steel

• Pros: Affordable, decent rust protection
• Cons: Not ideal for long-term outdoor use or harsh conditions
• Best for: Indoor applications and light-duty jobs

Nylon and plastic

• Pros: Low friction, won’t scratch surfaces, non-marring
• Cons: Less durable under heavy loads or heat
• Best for: Electronics, light fixtures, and areas needing insulation

Brass and copper

• Pros: Naturally conductive, decorative finish
• Cons: Softer materials, not for heavy loads
• Best for: Electrical grounding, decorative hardware

High-carbon steel

• Pros: Extra strength for heavy-duty use
• Cons: Prone to rust if not coated
• Best for: Structural work and high-stress fastening

What else to keep in mind

• Avoid mixing metals to prevent galvanic corrosion which can damage both the washer and fastener.
• Consider the environment: moisture, temperature, and load type all matter when choosing materials.

Material	cURL Too many subrequests.	cURL Too many subrequests.	cURL Too many subrequests.
Stainless Steel	Corrosion-resistant	More expensive	Outdoor, marine
cURL Too many subrequests.	Cost-effective, rust-resistant	Limited outdoor use	Indoor, light-duty
Nylon/Plastic	Low friction, non-marring	Not for heavy loads	Electronics, insulation
cURL Too many subrequests.	Conductive, decorative	Softer, less strong	Electrical, decorative
High-Carbon Steel	Strong, heavy-duty	Rust-prone without coating	Structural, high load

For easy shopping, check out Vast’s material-specific washer kits tailored to your project needs. They make matching the right washer to your environment simple and hassle-free.

How to Choose the Right Washer Step-by-Step

Picking the right washer can save you headaches down the road. Here’s a simple process to follow:

Step 1: Assess the load type

Ask yourself if the load is static (steady) or vibrating. For vibration-prone environments, spring or lock washers work best to keep things tight.

Step 2: Match size to your fastener

Check the washer’s inner diameter (ID) and outer diameter (OD) so it fits your bolt or screw perfectly. Use the ANSI standards chart to ensure accurate sizing.

Step 3: Consider the environment

Think about moisture, temperature, and exposure. Stainless steel washers suit outdoor use because they resist corrosion, while zinc-plated steel might be fine indoors.

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Common mistakes to avoid

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