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Best Flat Washers

Discover a wide selection of flat washers in stainless steel, zinc-plated, and more for secure fastening in industrial, automotive, and home projects. Ideal for distributing load and preventing surface damage.

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Lordhardware 200 Pack 10# SAE Flat Washers 1/2" OD 304 Stainless Steel - Corrosion Resistant Metal Washers for Automotive & DIY

These SAE standard 10# flat washers with 1/2'' OD come in a 200-pack of 304 stainless steel for superior corrosion, rust, and oxidation resistance. Buy them for reliable performance in household electrical, automotive, and hydraulic projects.

  • Unmatched corrosion resistance thrives in high-heat, cold, or wet environments for years of reliable use
  • Rust and oxidation proof to protect connections in automotive, electrical, and hydraulic applications
  • SAE standard 10# sizing with 1/2'' OD ensures precise, secure fits every time
  • Bulk 200-pack delivers exceptional value for DIYers, mechanics, and professionals
  • Versatile for home appliances, car garages, fuel lines, and more

Premium 304 stainless steel build for top-tier durability and longevity. Excellent resistance to corrosion, rust, and extreme temperatures. Generous 200-piece pack suits large projects and frequent use.

Exhibits weak magnetic properties typical of 304 stainless steel. Specific 10# size limits use in non-standard applications. May require tools for installation in tight spaces.

ARP 2008539 10-Pack Premium Chrome Moly Washers - 7/16" ID Chamfered, 13/16" OD, .120" Thick for Race Engines

ARP 2008539 provides a 10-pack of parallel-ground, hardened chrome moly washers with 7/16" chamfered ID, 13/16" OD, and .120" thickness. Perfect for engine builders and racers stocking reliable hardware to avoid fastener failures.

  • Superior chrome moly build delivers unmatched strength for high-stress engine applications
  • Parallel-ground and hardened surfaces ensure precise, reliable fastening every time
  • Black oxide finish resists corrosion for long-lasting performance in harsh environments
  • Chamfered 7/16" inner diameter prevents edge damage and eases installation
  • Exact 13/16" OD and .120" thickness fit demanding OEM and custom race setups

Premium materials outperform standard washers in racing conditions. Hardened construction enhances durability and load-bearing capacity. Chamfered edges simplify assembly and reduce bolt stress.

Specific dimensions limit use to compatible 7/16" bolt applications. Premium quality may exceed needs for casual or low-performance projects.

Kuprowin 5/8" Black Stainless Steel Flat Washers 1-5/16" OD, 30 Pack - Corrosion-Resistant SAE Washers for Bolts

Kuprowin 5/8" black stainless steel flat washers feature precise 1-5/16" outer diameter and 304 stainless construction for superior strength and corrosion resistance. DIYers and professionals should buy them for reliable indoor/outdoor bolting applications.

  • Exceptional corrosion resistance protects against rust in wet or outdoor conditions
  • 304 stainless steel delivers high strength for secure, long-lasting fastening
  • Black coating offers a sleek, professional finish that resists chipping
  • Precise 5/8" inner diameter ensures perfect fit over standard bolts
  • Thin 0.075" profile distributes load evenly without adding bulk

Durable 304 stainless steel with black finish for corrosion protection. Exact sizing for 5/8" bolts with 1-5/16" outer diameter. Generous 30-pack quantity for value and convenience.

Black finish may show wear in highly abrasive environments. Specific to 5/8" bolts, not interchangeable with other sizes. Thin profile suits light to medium duty, not extreme heavy loads.

300-Piece 304 Stainless Steel Flat Washers Assortment Kit - 8 SAE Sizes #6-#12, 1/4-1/2" for Bolts, Screws & DIY Repairs

This 300-piece SAE flat washers kit features 8 sizes from #6 to 1/2 inch, crafted from corrosion-resistant 304 stainless steel. Its bulk quantity and organized compartments make it perfect for mechanics, DIY enthusiasts, and marine professionals tackling repairs and maintenance.

  • Rust-proof 304 stainless steel ensures durability in wet, salty, or outdoor conditions like marine and automotive use
  • 8 versatile SAE sizes (#6 to 1/2") handle everything from small screws to large bolts in one convenient kit
  • 300 pieces per set (15-55 per size) provide bulk savings, eliminating frequent reordering for pros and hobbyists
  • Organized compartments keep washers sorted and ready for quick grabs during projects
  • Precision 1-2mm thickness distributes loads evenly, resists vibration, and protects fasteners from damage

Superior corrosion resistance ideal for harsh environments. Wide range of 8 SAE sizes fits most common bolt applications. Cost-effective bulk pack with easy organization.

Limited to SAE sizes only, no metric equivalents. Thickness range (1-2mm) may not suit ultra-thin applications. Organizer box could wear with heavy daily professional use.

ZQZ 108pcs 304 Stainless Steel Flat Washers Assortment Kit - 12 Metric Sizes M3-M12 Wide Fender Washers for DIY & Construction

This ZQZ kit provides 108 flat washers in 12 metric sizes from M3 to M12, made of corrosion-resistant 304 stainless steel to prevent bolt loosening from vibration. DIYers, furniture repairers, and builders should buy it for its versatile, organized fastening solutions.

  • Versatile 12-size assortment tackles DIY furniture fixes to heavy construction projects
  • Rust-proof 304 stainless steel endures outdoor exposure and extends fastener life
  • Prevents nuts, bolts, and screws from loosening due to vibration and friction
  • Uniform thickness and smooth edges distribute loads evenly for machine stability
  • Organized clear case keeps 108 pieces sorted and easy to carry without mix-ups

Durable 304 stainless steel resists rust and corrosion effectively. 12 diverse sizes in 108 pieces cover most metric fastening needs. Convenient storage case prevents loss and simplifies organization.

Limited to metric sizes, no imperial equivalents included. Slightly magnetic despite stainless steel construction. Quantities per size not evenly distributed or specified.

QKP 143pcs Flat Rubber Washers Assortment Kit, 10 Sizes 7-30mm Gaskets for Pipes, Hoses, Screws, Plumbing, Garden Bolts & Shower Fittings

QKP 143Pcs Flat Rubber Washers Kit provides 10 sizes from 7mm to 30mm for versatile sealing in plumbing, hoses, and DIY projects. Its high-quality rubber ensures leak-proof performance and durability, perfect for DIYers, plumbers, and handymen.

  • Versatile 143-piece kit with 10 precise sizes (7-30mm) covers most household and DIY sealing needs without hunting for matches
  • Premium rubber delivers superior flexibility, leak prevention, and vibration reduction for long-lasting protection
  • Ideal for plumbing, hoses, taps, pipes, showers, and garden bolts to ensure secure, watertight connections
  • Sturdy storage box keeps sizes organized and accessible, saving time and space in your toolkit
  • Flat design creates tight seals against gaps, blocking water, air, or oil leaks while protecting parts from wear

Abundant quantity and size variety for broad applications. Excellent water and wear resistance for reliable performance. Convenient organized storage box.

Limited pieces per larger sizes may require restocking for heavy use. Rubber may soften in extreme heat over time. Not ideal for high-pressure industrial applications.

kvohlum 50 Pack 5/16" 304 Stainless Steel Flat Washers Black Finish - Corrosion-Resistant for Bolts, Screws, Outdoor Use

kvohlum's 50-pack of 5/16" 304 stainless steel flat washers with black finish excels in corrosion resistance and load distribution to prevent fasteners from pulling through surfaces. Buy these for electrical repairs, factory maintenance, furniture fixes, or outdoor construction projects.

  • Distributes load evenly under fastener heads for secure, damage-free holding
  • 304 stainless steel with black coating resists corrosion in harsh environments
  • Prevents bolts and nuts from pulling through surfaces during heavy use
  • High tenacity and temperature resistance for reliable performance
  • Ideal for electrical repairs, factory maintenance, and outdoor projects

Superior corrosion and heat resistance from 304 SS and black finish. Enhances fastener stability by spreading load effectively. Versatile for repairs in electrical, furniture, and construction applications.

Thin 0.07" thickness may limit use in extremely heavy-duty applications. Black finish could wear over time in abrasive environments. Fixed 50-piece pack may be more than needed for small jobs.

zcgxbel 650-Piece Nylon Flat Washers Assortment Kit, 7 Sizes M3-M12 Black Plastic for Screws Bolts, Durable Washer Set for DIY & Commercial Use

This 650-piece nylon flat washers kit includes 7 sizes from M3 to M12, packed in an organized transparent box with labeled compartments. Its high-hardness nylon offers superior wear, corrosion resistance, and insulation, making it perfect for DIYers, household repairs, and professionals in harsh environments.

  • Versatile 7-size range (M3-M12) covers all your screw and bolt fastening needs
  • Durable nylon construction resists corrosion, wear, and harsh weather for long-lasting reliability
  • Excellent insulation properties protect against electrical hazards in maintenance tasks
  • Generous 650-piece count ensures ample supply for multiple projects
  • Organized storage box with labeled grids for instant size identification and easy access

Comprehensive sizing from M3 (200pcs) to M12 (16pcs) for broad compatibility. High-quality nylon provides hardness, weather resistance, and insulation. Convenient transparent box keeps washers sorted and portable.

Fewer pieces in larger sizes (e.g., only 16 each for M10/M12). Requires verifying sizes and nylon material before purchase to ensure fit. Nylon may compress under extreme high-load applications.

BoltDropper 100-Pack Stainless Steel Fender Washers 1/4 x 1-1/4 Inch - Rust-Resistant Flat Washers for Bolts, Screws in Wood, Metal, Wet Areas

BoltDropper's pack of 100 stainless steel fender washers measures 1/4 x 1-1/4 inches with 0.050-inch thickness for reliable fastening in wood, metal, and wet environments. Their 18-8 stainless steel construction provides standout corrosion resistance, making them perfect for DIYers, contractors, and marine applications.

  • Boosts fastening strength with wide surface area for secure holds on screws and bolts in demanding projects
  • Shields against rust and corrosion in wet, outdoor, or marine settings for long-lasting performance
  • Evenly spreads load to minimize surface damage and prevent loosening from vibrations or heavy use
  • Versatile for construction, plumbing, automotive, and DIY tasks requiring dependable reinforcement
  • Distributes pressure effectively to enhance stability under heavy loads or dynamic conditions

Superior corrosion resistance from 18-8 stainless steel for indoor/outdoor durability. Wide 1-1/4-inch outer diameter provides excellent load distribution. Generous 100-pack quantity offers great value for frequent use.

Thin 0.050-inch thickness may not suffice for ultra-heavy industrial loads. Fixed 1/4-inch size limits use with larger or smaller fasteners. Bulk pack of 100 may overwhelm users needing only a few washers.

Hillman 280062 7/16-Inch Zinc Flat Washers 50-Pack - Corrosion-Resistant for Decks, Fences & Bolts

Hillman 280062 7/16-Inch flat washers in a 50-pack provide a greater bearing surface to prevent nuts or bolts from tearing through materials during assembly. Their zinc coating delivers corrosion resistance, making them ideal for DIYers building decks, fences, or any outdoor projects with coarse threaded bolts.

  • Zinc coating shields against rust and corrosion for long-lasting outdoor performance
  • Expanded bearing surface distributes pressure to avoid material damage from bolts
  • SAE fine design fits coarse threaded bolts securely in decks and fences
  • Boosts bolt or screw clamping force for stronger, more reliable fastenings
  • Matches fastener finishes for a uniform, professional look on projects

Corrosion-resistant zinc finish extends washer lifespan in wet environments. Prevents pull-through damage with superior bearing surface. Compatible with coarse bolts for common deck and fence applications.

Specific 7/16-inch inner diameter limits use to matching bolt sizes. Zinc plating may not withstand extreme marine or chemical exposure. SAE fine spec tailored for coarse threads, not ideal for all bolt types.

Whether you're tackling a heavy-duty industrial assembly, automotive repair, or home DIY project, flat washers are essential fasteners that provide a smooth, stable surface between bolts and nuts. In our Flat Washers category under Industrial & Scientific > Fasteners > Washers, you'll find high-quality options like stainless steel packs, zinc-plated varieties, and assortment kits from trusted brands, ensuring even load distribution, corrosion resistance, and reliable performance.

What Are Flat Washers and Why Do You Need Them?

Flat washers are simple yet indispensable components—thin, disc-shaped rings with a central hole designed to fit over screws, bolts, or nuts. They act as spacers and load distributors, preventing fasteners from digging into surfaces, reducing loosening from vibration, and enhancing joint integrity. Unlike beveled or fender washers, standard flat washers have a uniform thickness and flat profile, making them versatile for general-purpose use.

Available in materials like 18-8 (304) stainless steel for corrosion resistance in harsh environments, zinc yellow chromate-plated steel for added protection, and high-grade options for extreme loads, these washers come in various sizes such as 1/4-inch, 5/16-inch, and SAE standards like 10# or Grade 8. Packs range from small 25-piece sets to massive 550-piece assortments, suiting everyone from professionals to hobbyists.

Key Features to Consider When Buying Flat Washers

Selecting the right flat washer boils down to matching specs to your project needs. Here's what to evaluate:

  • Material: Stainless steel (304 or 18-8) excels in outdoor, marine, or chemical-exposed applications due to rust resistance. Zinc-plated or chromate finishes suit indoor or mildly corrosive settings.
  • Size and Standards: Check inner diameter (ID) for bolt fit (e.g., 7/16-inch), outer diameter (OD) for coverage (like 1-inch fender styles), and thickness (0.078-inch common). Opt for SAE, USS, or metric (M3-M12) based on your hardware.
  • Quantity and Pack Type: Single-size packs like the Hillman 50-pack 7/16-inch or assortment kits covering 12 sizes for versatility.
  • Finish and Grade: Black finish for aesthetics, Grade 8 for high-strength demands.
  • Compliance: Look for ASME B18.22.1 standards to ensure quality and interchangeability.

Brands like KANSPHY offer durable 1/4-inch stainless options in 100-packs, while Lordhardware provides 200-piece 10# SAE washers for bulk needs.

Common Applications for Flat Washers

Flat washers shine in diverse scenarios:

  • Industrial & Construction: Securing machinery, structural beams, and HVAC systems.
  • Automotive: Engine mounts, suspension components, and exhaust repairs—especially stainless for undercarriage exposure.
  • Marine & Outdoor: Boat hardware and decking where corrosion is a threat.
  • DIY & Home: Furniture assembly, shelving, and plumbing fixtures.
  • Electronics & Appliances: Preventing overtightening on delicate surfaces.

For vibration-prone setups, consider pairing with options from our Lock Washers category. Assortment kits from Aienxn (550 pieces across SAE sizes) or Nuepuxo (108 pieces metric) are perfect for workshops stocking multiple projects.

How to Choose the Perfect Flat Washer for Your Project

Start by measuring your bolt diameter—match ID precisely. For load-heavy jobs, prioritize thicker, higher-grade washers like Small Parts' Grade 8 steel. In wet areas, stainless is non-negotiable; check packs from BatesChoice's 100-piece 1/4-inch fender washers for broad coverage.

Consider OD for surface protection—larger for soft materials like wood or aluminum. Bulk buyers save with kits spanning 2# to 1/2-inch, ideal for unpredictable needs. Always verify compatibility with your fasteners to avoid slippage or failure.

Pro tip: Test a small pack first for fit, then scale up. Our selection ensures you get reliable performers without guesswork.

Frequently Asked Questions (FAQ)

What is the difference between flat washers and fender washers?

Flat washers have a standard OD relative to ID for general use, while fender washers feature a larger OD for greater load distribution on oversized holes or soft surfaces, like in automotive fenders.

Are stainless steel flat washers better than zinc-plated?

Stainless (304/18-8) offers superior corrosion resistance for outdoor/marine use, while zinc-plated is cost-effective for dry, indoor applications with good rust protection.

What sizes are most common for flat washers?

Popular SAE sizes include 1/4", 5/16", 3/8", and #8-#12 machine screw sizes; metric M3-M12. Assortments cover these for versatility.

Can I use flat washers with any bolt type?

Yes, as long as ID matches the bolt shank. Use SAE with imperial hardware, metric with M-series for best fit.

How many flat washers do I need per bolt?

Typically one under the nut and one under the head, but add more for high-vibration or soft-material applications to prevent pull-through.