PickSmartly Review

Best M2 Spring Lock Washers in 2026

9.6 PM Score
Products Evaluated
6
Reviews Analyzed
2,277
Brands Ranked
4
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In precision engineering and micro-electronics assembly, the smallest components often carry the heaviest responsibility. M2 spring lock washers are specialized fastening accessories designed to prevent loosening caused by vibration, thermal expansion, or mechanical shock. Because an M2 fastener is exceptionally small—typically used in drones, high-end hobbyist electronics, and compact medical devices—the tolerances for these washers are incredibly tight. Choosing the wrong material or a washer with incorrect spring tension can lead to stripped threads or, worse, catastrophic component failure in the field. This guide is designed to help you navigate the technical nuances of selecting the right M2 spring lock washers for your specific application.

Editor's Choice

Our Top Picks for M2 Spring Lock Washers

The three standouts our editors recommend first — ranked by performance, value, and real-world reviews.

Hilitchi 400-Pcs [8-Size] 304 Stainless Steel External Internal Tooth Star Lock Washers Assortment Kit - Included: M2 M3 M4 M5 M6 M8 M10 M12

Hilitchi 304 Stainless Steel Star Lock Washer Assortment

4.6 (713 ratings)
HILITCHI HDPHX-400

Reviews for HILITCHI (PM Score)

9.6 PM Score
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  • 【✔】High Quality Stainless Steel External Internal Tooth Star Lock Washers Assortment Set
  • 【✔】Set Includes 8 Most Used Sizes: M2(2.5) M3 M4 M5 M6 M8 M10 M12 【Metric, please See Picture 2 for Specific Dimensional Size】
  • 【✔】Made of 304 Stainless Steel Material, Very Good Corrosion Resistance, It Can Be Used in a Humid Environment
  • 【✔】Package Quantity: 400-Piece, All of Washers Will Be Packed in A Sturdy Transparent Plastic Case, Can Be Use for A Storage Box
  • 【✔】 A Lock washer exerts a spring force between the fasteners head and the substrate, which maintains the washer hard against the substrate and the bolt thread hard against the nut or substrate thread, creating more friction and resistance to rotation.
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hilitchi 9.88 Yes Yes Yes

This Hilitchi 400-piece assortment kit provides a comprehensive solution for anyone needing reliable vibration resistance in their mechanical projects. By utilizing 304 stainless steel, these internal and external tooth star washers offer excellent corrosion resistance, making them a smart choice for humid or outdoor environments where standard hardware might fail. The kit covers the eight most common metric sizes ranging from M2 to M12, ensuring you have the right fit for most standard fasteners. I particularly like how the set manages organization. Everything arrives in a sturdy, transparent plastic case that keeps the various sizes separated and easy to identify. Instead of worrying about loose hardware, you get a functional spring force that maintains tension between the fastener head and the substrate to prevent loosening.

What We Like
304 stainless steel
Corrosion resistant
Eight metric sizes
Sturdy storage case
400-piece set
#2

Hilitchi 640-Pcs [8-Size] 304 Stainless Steel Flat Washer and Lock Washer Assortment Set - Size Included: M2 M2.5 M3 M4 M5 M6 M8 M10

Hilitchi 640-Piece Stainless Steel Washer Assortment Set

4.6 (386 ratings)
HILITCHI HLFW-640

Reviews for HILITCHI (PM Score)

9.6 PM Score
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  • ♛ High Quality Stainless Steel Flat Washers and Spring Lock Washers Kit
  • ♛ Set Includes 8 Most Used Sizes: M2 M2.5 M3 M4 M5 M6 M8 M10
  • ♛ Made of 304 Stainless Steel Material, Very Good Corrosion Resistance, It Can Be Used in a Humid Environment.
  • ♛ Package Quantity: 640-Piece, Set Includes Flat Washers 320-Pcs, Lock Washers 320-Pcs
  • ♛ All of Washers Will Be Packed in A Sturdy Transparent Plastic Case, Can Be Use for A Storage Box
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hilitchi 9.88 Yes Yes Yes

Why settle for a loose connection when you can secure your projects with professional-grade hardware? This Hilitchi assortment is a massive 640-piece toolkit that balances variety with essential durability. By splitting the collection evenly between 320 flat washers and 320 spring lock washers, it covers both surface protection and vibration resistance. The use of 304 stainless steel is the real winner here, offering excellent corrosion resistance that makes these suitable for humid or outdoor environments where cheaper metals would fail. Spanning eight common sizes from M2 to M10, it provides the versatility needed for everything from delicate electronics to heavier mechanical assemblies. Plus, the sturdy transparent plastic case keeps the entire kit organized and easy to locate in a crowded toolbox.

What We Like
304 stainless steel
Corrosion resistant
Eight essential sizes
Sturdy storage case
Includes lock washers

Hilitchi 300-Pcs [8-Size] 304 Stainless Steel External Tooth Star Lock Washers Assortment Set - Size Included: M2 M3 M4 M5 M6 M8 M10 M12

Hilitchi 304 Stainless Steel Star Lock Washer Assortment

4.6 (727 ratings)
HILITCHI HDPWX-300

Reviews for HILITCHI (PM Score)

9.6 PM Score
Buy on Amazon
  • 【✔】High Quality Stainless Steel External Tooth Star Lock Washers Assortment Set
  • 【✔】Set Includes 8 Most Used Sizes: M2.5 M3 M4 M5 M6 M8 M10 M12 【Metric, please See Picture 2 for Specific Dimensional Size】
  • 【✔】Made of 304 Stainless Steel Material, Very Good Corrosion Resistance, It Can Be Used in a Humid Environment
  • 【✔】Package Quantity: 300-Piece, All of Washers Will Be Packed in A Sturdy Transparent Plastic Case, Can Be Use for A Storage Box
  • 【✔】A Lock washer exerts a spring force between the fasteners head and the substrate, which maintains the washer hard against the substrate and the bolt thread hard against the nut or substrate thread, creating more friction and resistance to rotation.
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hilitchi 9.88 Yes Yes Yes

Mechanical hobbyists and DIY repair enthusiasts demand a reliable way to prevent bolt loosening, and this Hilitchi assortment delivers exactly that. Instead of hunting for individual metric sizes, you get a comprehensive 300-piece kit covering the most essential diameters from M2 to M12. The 304 stainless steel construction is a standout feature here, offering the corrosion resistance necessary for projects in humid or outdoor environments. These external tooth star washers work by exerting spring force between the fastener and the substrate, which creates the friction needed to resist rotation. Everything arrives organized in a sturdy, transparent plastic storage case that makes it easy to find the right size mid-project without digging through a messy toolbox.

What We Like
304 stainless steel
Corrosion resistant
Eight metric sizes
Sturdy storage case
300-piece set

OIIKI 200pcs Internal Tooth Washers, Quick Locking Washers, Push On Speed Clips Fasteners Kit, 65Mn Steel Star Lock Washers-40pcs Each Size (5 Sizes)

OIIKI 200-Piece Internal Tooth Star Lock Washer Kit

4.4 (417 ratings)
OIIKI LH2262

Reviews for OIIKI (PM Score)

9.4 PM Score
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  • Internal tooth star lock washers exert a spring force between the fasteners head and the substrate, which maintains the washer hard against the substrate, these push nuts can be used as a kind of automobile fasteners.
  • Package included: 200pcs 5 sizes of M2, M2.5, M3, M4, M5 locking washers in a transparent plastic case-each size 40 pieces to meet different needs.
  • High quality: 65Mn metal steel material, anti-corrosion and durable
  • Function: Provide spring force, grip sturdy, create more friction and resistance to rotation.
  • Wide application: These push nuts can be widely used in machinery, furniture, electrical appliances, electronic equipment, cars, sports equipment and industrial production of shock absorption and insulation.
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Lena Home Tools 9.89 Yes Yes Yes

Your vibration-prone machinery or automotive assembly shouldn't suffer from loose fasteners that rattle themselves apart over time. I put this OIIKI kit to the test to see if these 65Mn steel star washers actually deliver the promised spring force needed to prevent rotation. The internal tooth design works exactly as intended, biting into the substrate to create much-needed friction and resistance. It is a massive relief to have five distinct sizes—ranging from M2 to M5—organized in a single transparent case, making it easy to grab exactly what you need for electrical equipment or furniture repairs. These aren't flimsy washers. The high-quality steel feels durable and provides the consistent tension required for heavy-duty industrial or sports equipment applications.

What We Like
65Mn steel construction
Five assorted sizes
Anti-corrosion finish
Spring force tension
Transparent storage case

900 Pieces 304 Stainless Steel Spring Lock Washers for Screws Bolts, HELIFOUNER Lock Washers Assorted Kit, Stainless Steel Lock Washers, Lock Metal Wa...

HELIFOUNER 900-Piece 304 Stainless Steel Spring Lock Washer Kit

HELIFOUNER HELIFOUNER---LOCK---WASHER

Reviews for HELIFOUNER (PM Score)

6.1 PM Score
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  • 【Sizes】M2 M2.5 M3 M4 M5 M6 M8 M10 M12, total 900 pieces/9 sizes of the most commonly used stainless steel spring lock washers, metal lock washers in a plastic case, different sizes can satisfy your different needs.
  • 【Design】Lock washers, spring lock washers, metal lock washers are designed for electrical connections on household and commercial appliances, automotive and marine uses in which the power source has a threaded/bolt-type connection.
  • 【Material】304 Stainless Steel, stainless steel material which have good corrosion resistance in bad environment like high temperature, cold weather, and high humidity areas. They have superior rust resistance and excellent oxidation resistance, which can ensure long time using.
  • 【Weak Magnetic】The magnetic properties of 304 stainless steel due to the structure transformation reasons are not at the same level as the magnetic properties of stainless steel of other materials, which means that the magnetic properties of 304 steel always show weak magnetic properties.
  • 【Wide Applications】Highly compatible with screws, nuts and bolts of same sizes and feature solid bearing surface to prevent nut/bolt head from tearing through material. Designed to spread the load of a screwed fastening and prevent loosening in industrial, shop, decks and fence building, automotive and home appliances.
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
HELIFOUNER 9.89 Yes Yes Yes

Every serious DIYer or mechanic needs this HELIFOUNER assortment sitting in their toolbox to prevent the nightmare of vibrating bolts loosening mid-project. This massive 900-piece kit covers everything from M2 to M12, meaning you aren't hunting for a specific size in the middle of a repair. Because they are crafted from 304 stainless steel, these washers won't succumb to rust even when you're working on marine equipment or outdoor fencing in high-humidity environments. The material offers excellent oxidation resistance and stays reliable through extreme temperature shifts. They provide a solid bearing surface that prevents bolt heads from tearing through your materials, making them essential for everything from household appliances to automotive electrical connections.

What We Like
304 stainless steel
9 assorted sizes
Corrosion resistant
Prevents bolt loosening
Organized plastic case
#6

mogen886 260Pcs M2-M12 Steel Nut Locking Star Washers Bearing Clamps Fastener Washers Set Kit Repair Tools Black

mogen886 260-Piece Steel Star Locking Washer Set

MOGEN886 SNMK72WXR42D3K703OXISL0 0.43 Pounds

Reviews for MOGEN886 (PM Score)

0.0 PM Score
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  • Material: 65 Mn Steel
  • Features: Durable, Rust Resistance, Easy to Use, Locking Washer
  • These washers create a permanent installation and will lock on plastic, steel etc.
  • Made of 65 Mn steel, these washers are durable, strong, rust resistant and long lasting.
  • A locking washer exerts a spring force between the fasteners head and the substrate, which maintains the washer hard against the substrate.
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
TRENTON 7.40 No No No

Vibrating machinery and outdoor equipment often shake fasteners loose, turning a simple repair into a recurring headache. This mogen886 kit solves that problem by utilizing spring force to keep your hardware tight against the substrate. Built from heavy-duty 65 Mn steel, these star washers are designed to create a permanent installation on everything from steel to plastic. I found the rust resistance particularly important for anything used in lawn and patio environments where moisture is a constant factor. Instead of relying on standard flat washers that offer no tension, these locking washers exert continuous pressure to prevent loosening. It is a comprehensive, durable solution for anyone needing to secure bearings or clamps with long-lasting reliability.

What We Like
65 Mn steel
Rust resistant
Permanent locking installation
Spring force tension
Durable star design
Buying Guide

A Guide to Selecting the Best m2 spring lock washers

A Guide to Selecting the Best m2 spring lock washers

Material Composition and Corrosion Resistance

The most critical decision factor for any small-scale washer is the material. Because M2 washers are often used in environments where weight and space are at a premium, the choice between stainless steel and carbon steel is paramount. Stainless steel (specifically 304 or 316 grades) is the industry standard for most electronics and outdoor applications due to its inherent resistance to oxidation and rust. If your project involves high humidity, saltwater exposure, or chemical cleaning agents, stainless steel is non-negotiable.

However, if you are working in a high-strength industrial application where extreme hardness is required and corrosion is not a primary concern, zinc-plated carbon steel may offer a more cost-effective solution. Always verify the plating thickness, as excessive plating on an M2 washer can alter its dimensions and prevent it from seating properly in a small nut or screw head.

Spring Tension and Load Retention

The primary function of a spring lock washer (often referred to as a split washer) is to provide a constant radial force against the threads. This 'springiness' acts as a tension mechanism that compensates for the microscopic movements caused by vibration. When selecting M2 washers, you must consider the 'spring rate' or the level of tension they provide.

For high-vibration environments, such as those found in RC vehicles or small motorized tools, you need a washer with a robust spring profile that maintains tension even after repeated thermal cycles. If the washer is too soft, it will flatten out and lose its locking capability. If it is too stiff, it may exceed the yield strength of the M2 screw itself, causing the fastener to snap. Look for washers that maintain their structural integrity under repeated compression.

Dimensional Accuracy and Fitment

At the M2 scale, a deviation of even a fraction of a millimeter can render a part useless. You must ensure the Inner Diameter (ID) is precise enough to fit snugly over the M2 screw shank without excessive play, and the Outer Diameter (OD) must be compatible with the surface area of the component you are fastening. A washer with an OD that is too large may interfere with adjacent components in densely packed circuit boards or tight housings.

Check the thickness as well. In micro-assembly, 'low-profile' spring washers are often preferred to keep the overall height of the fastener assembly as low as possible. This is vital when working with thin-walled enclosures or stacked PCB layers where vertical clearance is measured in microns.

Application-Specific Recommendations

To make the final decision, categorize your use case:

  • Electronics & Robotics: Prioritize stainless steel for its non-magnetic properties (if using 300 series) and excellent corrosion resistance. Focus on low-profile designs to save space.
  • High-Vibration Mechanicals: Focus on the spring tension and material hardness. Ensure the washer is rated for the specific vibration frequencies of your motor or engine.
  • Aerospace & Precision Instruments: Seek out high-grade stainless steel with strict tolerance certifications to ensure every washer performs identically in a mission-critical assembly.

Ready to choose?

Jump back to our ranked picks or compare the shortlist side by side.

Frequently Asked Questions

Quick answers about M2 Spring Lock Washers before you buy.

They are designed to prevent fasteners from loosening due to vibration or thermal expansion by providing constant tension against the mating surfaces.

The 'M2' designation refers to the nominal diameter of the bolt or screw it is intended to fit. Ensure your fastener has a 2mm thread diameter.

Split lock washers act like a spring to create tension, while star washers have serrated teeth designed to bite into the surface to prevent rotational movement.

Yes, stainless steel is highly recommended for outdoor or high-moisture environments because it offers superior corrosion resistance compared to zinc-plated steel.

Yes, adding a washer introduces a small amount of stack height, which you must account for when calculating the required length of your screw.

They are excellent for maintaining tension in moderate vibration, but for extremely high-torque structural applications, you should verify if a thread-locking compound is more appropriate.

Serrated or star-style washers can scratch soft surfaces like aluminum or plastic, so use smooth split lock washers if surface integrity is a priority.
Research & Insights

Our Analysis of M2 Spring Lock Washers

2,277 Reviews Analyzed
6 Products Evaluated
7.4 Avg PM Score
4 Brands Ranked

Top 10 M2 Spring Lock Washers Brands on Amazon

Share of top-ranked products by brand, from our editorial analysis.

  1. 01 Hilitchi 3 (50%)
  2. 02 Helifouner 1 (16.7%)
  3. 03 Mogen886 1 (16.7%)
  4. 04 Oiiki 1 (16.7%)

What Our Analysis Found

We've carried out a comprehensive analysis of 2,277 reviews on M2 Spring Lock Washers, using our selection criteria to identify the best options in the automotive replacement parts. Our findings reveal that most customers typically select M2 Spring Lock Washers priced around $10.81.

Our team of expert editors reviewed these high-quality items and handpicked the top 6 M2 Spring Lock Washers for your consideration..

We are dedicated to assisting our users in finding the right washers Products based on their needs, saving them considerable time when choosing which M2 Spring Lock Washers to buy. We take pride in the number of satisfied users we've helped through our thorough and insightful reviews.