Safety & Security

The Best Tooth Lock Washers

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Our picks are based on Amazon bestseller rankings, verified customer ratings, and product availability. We update our recommendations regularly to ensure accuracy.

Tooth lock washers are crucial fasteners engineered to resist loosening caused by vibration and torque, providing enhanced security in mechanical assemblies. They are widely used across various applications, from automotive repairs to home improvement projects, ensuring connections remain stable over time. Products were evaluated based on material strength, corrosion resistance, assortment variety, ease of operation, and feature analysis.

Best Overall
Vifmy External Tooth Lock Washers Assortment Kit(500 Pack),M2.5 M3 M4 M5 M6 M8 M10 M12 Metric 304 Stainless Steel External Star Washer Sets

Vifmy External Tooth Lock Washers Assortment Kit(500 Pack),M2.5 M3 M4 M5 M6 M8 M10 M12 Metric 304 Stainless Steel External Star Washer Sets

$9.99

This kit offers a comprehensive selection of 304 stainless steel external tooth washers, providing excellent corrosion resistance and a generous quantity for diverse applications.

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Best Budget
260pcs[9 Sizes] Black Starlock Internal Tooth Lock Washers Assortment Kit, M2/ M2.5/ M3/ M4/ M5/ M6/ M8/ M10/ M12

260pcs[9 Sizes] Black Starlock Internal Tooth Lock Washers Assortment Kit, M2/ M2.5/ M3/ M4/ M5/ M6/ M8/ M10/ M12

$6.99

The binifiMux kit provides a practical assortment of internal tooth washers made from 65Mn steel, offering a cost-effective solution for general-purpose internal locking needs.

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Best Premium
570Pcs External Tooth Lock Washers Multi-Tooth Star Locking Washers Assortment Kit 304 Stainless Steel Washer Sets M2.5 M3 M4 M5 M6 M8 M10 M12 Frequently Used in High-Vibration Environments

570Pcs External Tooth Lock Washers Multi-Tooth Star Locking Washers Assortment Kit 304 Stainless Steel Washer Sets M2.5 M3 M4 M5 M6 M8 M10 M12 Frequently Used in High-Vibration Environments

$8.88

With a large quantity of 304 stainless steel external tooth washers and explicit suitability for high-vibration environments, the MroMax kit stands out for demanding applications.

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No. 1
Vifmy External Tooth Lock Washers Assortment Kit(500 Pack),M2.5 M3 M4 M5 M6 M8 M10 M12 Metric 304 Stainless...
  • External Tooth Lock Washer: The metric external tooth star lock washers assortment kit contains 8 sizes 500 pcs, which are m2.5(100 pcs),m3(100 pcs),m4(100 pcs),m5(70 pcs),m6(50 pcs),m8(30 pcs),m10(30 pcs),m12(20 pcs) ,8 different sizes of external star...
  • 304 Stainless Steel: 304 Stainless steel external washers are made of high-strength materials with good corrosion resistance and long service life. Compared to galvanised materials, the oxidation resistance, corrosion resistance and rust resistance are...
  • Easy Operation: Internal tooth star washers are mainly used for nuts and bolts from rotating and loosening due to vibration and friction, and play a role in preventing loosening and fixing objects to ensure the stability of machines
  • Convenient Storage: Each of the 8 different sizes of external tooth lock washer are individually stowed by type in an easy to carry clear case.Easy to store and use,so that the rivnut will not be lost or mixed up during use
  • Wide Application: External tooth washer are highly compatible with screws, nuts and bolts of the same size and can be used to connect moving parts or to prevent loose connections, such as in furniture repair, outdoor construction, and electrical...
No. 2
qxayxa 330 Pcs External Tooth Star Lock Washers, Stainless Steel External Starlock Washers Assortment Set...
  • Exquisite Material: External internal tooth starlock washers are made of high-quality stainless steel, which is strong, not easy to deform or break, resistant to corrosion and rust, and can maintain good performance in any environment and is durable.
  • External Tooth Star Lock Washers: The star-shaped configuration of lock washers provides flexibility to apply a spring force between the fastener head and the substrate and hold the bolt threads firmly and forcefully against the nut or substrate threads...
  • Easy to Store: All star washers are stored in a transparent and sturdy storage box with compartments. Retaining washers are stored separately, well organized, easy to carry and find. There is no confusion during transportation and it is convenient to use.
  • Wide Range of Applications: Widely used in various screw fastening applications, suitable for electrical connections in electrical appliances, automobiles and ships, valves, machinery, doors and windows and other fields.
  • Package Includes: 330 pcs in total, size includes 20 pcs m10, 30 pcs m8, 50 pcs m6, 20 pcs m12, 60 pcs m2.5, 50 pcs m3, 50 pcs m4, 50 pcs m5 , the quantity is sufficient, and the size is rich to meet the needs of different fields.
No. 3
Vifmy Internal Tooth Star Lock Washers Assortment Kit(500 Pack), M2.5 M3 M4 M5 M6 M8 M10 M12 Metric...
  • Internal Tooth Lock Washer: The metric internal tooth star lock washers assortment kit contains 8 sizes 500 pcs, which are m2.5(100 pcs),m3(100 pcs),m4(100 pcs),m5(70 pcs),m6(50 pcs),m8(30 pcs),m10(30 pcs),m12(20 pcs) ,8 different sizes of internal star...
  • 304 Stainless Steel: 304 Stainless steel internal tooth washers are made of high-strength materials with good corrosion resistance and long service life. Compared to galvanised materials, the oxidation resistance, corrosion resistance and rust resistance...
  • Easy Operation: Internal tooth star washers are mainly used for nuts and bolts from rotating and loosening due to vibration and friction, and play a role in preventing loosening and fixing objects to ensure the stability of machines
  • Convenient Storage: Each of the 8 different sizes of internal tooth lock washer are individually stowed by type in an easy to carry clear case.Easy to store and use,so that the rivnut will not be lost or mixed up during use
  • Wide Application: Internal tooth washer are highly compatible with screws, nuts and bolts of the same size and can be used to connect moving parts or to prevent loose connections, such as in furniture repair, outdoor construction, and electrical...
No. 4
Biaungdo Internal Tooth Washers, 50 Pcs, 5 Sizes Star Locking Washers
  • Package Contents: You will receive 50 pieces of star-shaped locking washers with inner teeth. These include 10 pieces of M2x6mm, 10 pieces of M2.5x8mm, 10 pieces of M3x10mm, 10 pieces of M4x12mm, and 10 pieces of M5x14mm. Different size combinations can...
  • Preferred Material: The washer is made of high-quality 65mn metal steel material, which has excellent corrosion resistance and rust resistance, is durable, not easy to deform, and has a longer service life.Easy to install and use
  • Widely Used: Push nuts are widely used in shock absorption and insulation in various fields such as machinery and equipment, electronic equipment, automobiles, sports equipment, industrial production, etc.
  • Function: It provides excellent spring force between the fastener head and the substrate. The grip is very strong and can be used to fix cars, strollers, grills, chairs and other items.
No. 5
Vifmy 500PCS Internal Tooth Star Lock Washers, M2.5 M3 M4 M5 M6 M8 M10 M12 Push Nuts Assortment, Quick Speed...
  • Speed Locking Washers Size: Speed locking washers assortment kit contains 8 size types of washers, which are m2.5-8(100pcs),m3-9(100pcs),m4-12(70pcs),m5-14(60pcs),m6-16(60pcs),m8-18(50pcs),m10-20(30pcs),m12-25(30pcs),8 different sizes to meet different...
  • Steel Star Locking Washer: The push nuts assortment are made of high quality carbon steel material, which has high strength and can withstand certain loads and impacts, and can ensure the stability and working life of the star locking washer
  • Star Locking Washer Function: The starlock washers are one of the indispensable elements in most mechanical equipment, it has a variety of roles in fixing, supporting and damping. It uses spring pressure to regulate reinforced shaped objects and is used...
  • Wide Application: internal tooth lock washer is widely used in various fields, especially in machinery manufacturing, automobile manufacturing, shipbuilding, aerospace, rail transport and so on
  • Convenient Storage: Each of the 8 different sizes of push on locking washer are individually stowed by type in an easy to carry clear case. Easy to store and use, so that the star locking washer will not be lost or mixed up during use
No. 6
Ruibapa 550PCS External Tooth Lock Washers Assortment Kit,M2.5 M3 M4 M5 M6 M8 M10 M12 Starlock Washers...
  • External Tooth Lock Washers Material: Made of 304 stainless steel, with good corrosion resistance and long service life. Compared with galvanized materials, it has stronger oxidation resistance, corrosion resistance and rust resistance, and the service...
  • Starlock washers 550pcs includes eight sizes:m2.5(120 pcs),m3(120 pcs),m4(110 pcs),m5(70 pcs),m6(50 pcs),m8(30 pcs),m10(30 pcs),m12(20 pcs).
  • Widely used: the internal star washers is matched with the same type of screws, nuts and bolts, which can be used to connect moving parts or prevent loose connection, such as shock absorption and insulation in furniture maintenance, outdoor construction...
  • 550pcs internal lock washers is packed in a transparent box, with clear model classification, easy carrying and convenient storage, and the box can be reused.
  • 550pcs internal lock washers is packed in a transparent box, with clear model classification, easy carrying and convenient storage, and the box can be reused.
No. 7
260pcs[9 Sizes] Black Starlock Internal Tooth Lock Washers Assortment Kit, M2/ M2.5/ M3/ M4/ M5/ M6/ M8/ M...
  • 【√√】Product name: Internal Tooth Washers
  • 【√√】Material: 65Mn Steel; √√Main Color: Black;
  • 【√√】Package: 260pcs x Starlock Washer in one storage box
  • 【√√】Include sizes: M2, M3 x 9mm, M4 x 12mm, M5 x 12mm, M6 x 16mm, M8 x 18mm, M10 x 20mm, M12 x 25mm
No. 8
uxcell 100Pcs Internal Tooth Washers, 1/4-Inch Stainless Steel Internal Serrated Washer for Mechanical...
  • [Internal Tooth Washers]: Package Content 100pcs of Internal Tooth Washers; Inner Dia: 6.4mm/1/4"; Outer Dia: 13.2mm/0.518; Thickness: 1mm/0.04"; Color: Silver Tone.
  • [Material]: Made of stainless steel, it has high strength, high hardness, corrosion resistance, wear resistance, smooth and bright appearance, and strict standard workmanship so that it can be used for a long time.
  • [Features]: The internal tooth washer applies spring force between the fastener head and the base material, generating more friction and rotational resistance. The internal tooth structure of the washer can evenly distribute the tightening force of the...
  • [Easy Installation]: The internal tooth washers can be fixed on the shaft with simple pressure or rotation during installation. Installation is simple and convenient.
  • [Application]: It is widely used in various screw fastening applications and is suitable for various mechanical, electronic, construction, automotive and other connecting equipment and industrial production industries.
No. 9
uxcell 40Pcs 5/16 External Tooth Lock Washer, 304 Stainless Steel Multi-Tooth Star Washer Locking Fastener...
  • Size: 5/16" external tooth lock washer, 40pcs. Inner Diameter: 8mm/0.31 inch; Outer Diameter: 15.2mm/0.6 inch; Thickness: 0.84mm/0.03 inch
  • Material: These external tooth lock washers are made of 304 stainless steel, with high hardness, not easy to deform, corrosion resistance, fine workmanship, smooth surface, no burrs, and durability
  • Design: The lock washer applies spring force between the fastener head and the base, making the washer adhere tightly to the base, and the fasteners are firmly bonded. The external tooth design of the star washer can provide greater friction and rotation...
  • Installation: The star washer is easy to install and remove. Simply insert the washer into the screw and tighten the nut to complete the assembly. The multi-tooth washers are reusable and not easy to slip after installation
  • Wide Application: Lock washers are suitable for threaded and bolted connections in a variety of household and commercial appliances, as well as automotive and marine power supplies. They are widely used for vibration reduction and insulation in mechanical...
SaleNo. 10
uxcell M4 70Pcs External Tooth Washers, 304 Stainless Steel Tooth Locking Ring Washers Quick Speed Star Nut...
  • [SIZE & PACKAGE]: Our External Tooth Washers have a specification of M4, an outer diameter of 8mm/0.31", an inner diameter of 4.3mm/0.17", a total thickness of 1.5mm/0.06", a material thickness of 0.5mm/0.02". And the packaging includes 70pcs Locking...
  • [MATERIALS]: These serrated washers are made of 304 stainless steel material, which has high hardness and does not deform. They are suitable for indoor, outdoor, or humid environments, with fine craftsmanship, beautiful appearance, good corrosion...
  • [DESIGN]: Lock washers apply spring force between the fastener head and base, causing the washer to adhere tightly to the base and the bolt to adhere tightly to the nut, resulting in more friction and rotational resistance. Provide a locking effect to...
  • [EASY TO OPERATE]: Our locking fasteners are very convenient to use. You just need to prepare the appropriate screws, then insert the washers into the screws, and tighten the nuts to complete the assembly. Even beginners can operate seamlessly.
  • [WIDELY APPLICABLE]: Our locking washers are suitable for threaded and bolted connections of various household and commercial appliances, and automotive and marine power supplies. Widely used in mechanical equipment and industrial production for shock...

Last update on 2026-07-18 / Affiliate links / Images from Amazon Product Advertising API

How to Choose the Best Tooth Lock Washers

Material Composition and Durability

The choice of material for tooth lock washers significantly impacts their longevity and performance in specific environments. In practice, 304 stainless steel, as seen in the Vifmy and MroMax external tooth washer kits, offers superior corrosion resistance, making it ideal for outdoor, marine, or damp conditions. Users often report that stainless steel maintains its integrity longer in such challenging settings. Conversely, materials like 65Mn steel or carbon steel with a black oxide finish, found in binifiMux and some Vifmy internal tooth washer sets, provide high strength and a degree of corrosion protection suitable for indoor or less aggressive environments. While robust, carbon steel may require additional rust prevention in humid conditions.

Internal vs. External Tooth Design

The main difference in tooth design, internal versus external, dictates the washer's application and how it grips. External tooth lock washers, such as those from Vifmy (B0CP7YZ9JY) and MroMax, feature teeth that extend outward, digging into both the fastener head and the mating surface. This design typically offers a larger contact area and is often preferred for larger bolt heads or when maximum locking force is required to prevent rotation. Internal tooth lock washers, exemplified by binifiMux and Vifmy (B0CP8Z7JMC) internal kits, have teeth that point inward. These are generally chosen for smaller fastener heads or where a cleaner, less protruding finish is desired, as the teeth are concealed beneath the fastener head. Both designs function by creating tension and friction to resist loosening due to vibration.

Assortment Size and Metric Compatibility

Considering the variety and quantity of washers in an assortment kit is crucial for ensuring you have the right size for different projects. Kits like the 500-pack Vifmy assortments (both external and internal) and the 570-piece MroMax kit provide a wide range of metric sizes (e.g., M2.5 to M12), which is typically sufficient for most common tasks. These larger assortments reduce the need for multiple purchases and ensure compatibility with standard metric nuts and bolts. Smaller kits, such as the 260-piece binifiMux offering, might be suitable for specific projects or users with less frequent needs, but may require supplementing if a wider range of sizes or higher quantities of a particular size are regularly required. Always verify the included sizes match your typical fastener dimensions.

Pros & Cons

Vifmy External Tooth Lock Washers Assortment Kit(500 Pack),M2.5 M3 M4 M5 M6 M8 M10 M12 Metric 304 Stainless Steel External Star Washer Sets

Pros

  • Constructed from 304 stainless steel for excellent corrosion resistance.
  • Includes a generous 500-piece assortment covering 8 common metric sizes (M2.5-M12).
  • External tooth design provides a strong grip against the fastener head and surface.

Cons

  • May not be suitable for applications requiring an internal tooth design for aesthetics or clearance.
  • Specific strength ratings are not explicitly detailed in the product description.

260pcs[9 Sizes] Black Starlock Internal Tooth Lock Washers Assortment Kit, M2/ M2.5/ M3/ M4/ M5/ M6/ M8/ M10/ M12

Pros

  • Features a black oxide finish for a degree of corrosion protection and a sleek appearance.
  • Made from 65Mn steel, known for its high strength and elasticity.
  • Offers 9 metric sizes, providing good versatility for internal tooth applications.

Cons

  • The 260-piece count is smaller compared to other kits, potentially limiting for large projects.
  • 65Mn steel may not offer the same level of long-term corrosion resistance as 304 stainless steel in harsh environments.

570Pcs External Tooth Lock Washers Multi-Tooth Star Locking Washers Assortment Kit 304 Stainless Steel Washer Sets M2.5 M3 M4 M5 M6 M8 M10 M12 Frequently Used in High-Vibration Environments

Pros

  • Largest assortment in the top 5 with 570 pieces, ensuring ample supply for various tasks.
  • Explicitly mentioned as frequently used in high-vibration environments, indicating robust performance.
  • Made from 304 stainless steel for superior oxidation and corrosion resistance.

Cons

  • Only offers external tooth washers, limiting its use for internal-tooth specific applications.
  • The quantity of each specific size might vary, requiring users to check the breakdown for their needs.

Common Mistakes to Avoid

Overlooking Material Compatibility for Environment

A common pitfall is selecting a tooth lock washer based solely on size without considering the operational environment. For instance, using a 65Mn steel or carbon steel washer, like those in the binifiMux kit, in an outdoor or humid setting can lead to premature corrosion. In practice, fasteners in marine or consistently damp conditions demand the inherent corrosion resistance of 304 stainless steel, as offered by Vifmy (B0CP7YZ9JY) or MroMax products, to maintain their locking integrity.

Incorrect Tooth Type for the Application

Failing to differentiate between internal and external tooth designs can compromise the effectiveness of the lock washer. External tooth washers, such as those from MroMax, are typically chosen for their wider grip and are effective with larger bolt heads. Conversely, an internal tooth washer, like those in the Vifmy internal kit (B0CP8Z7JMC), is better suited for applications where the teeth need to be concealed or where the fastener head is smaller. Using the wrong type can result in insufficient locking force or an undesirable aesthetic.

Underestimating Assortment Needs

Many users underestimate the variety and quantity of washers required for ongoing projects. Opting for a smaller kit, such as the 260-piece binifiMux assortment, might seem economical initially. However, if multiple projects involve diverse metric sizes (M2.5 to M12) or require numerous pieces of a single size, a larger assortment like the 500-pack Vifmy kits often proves more practical and prevents repeated purchases or project delays due to missing components.

Frequently Asked Questions

What is the primary function of a tooth lock washer?
Tooth lock washers are designed to prevent nuts and bolts from loosening due to vibration, thermal expansion, or torque. They achieve this by digging their teeth into both the fastener head and the mating surface, creating a secure, high-friction connection.
What is the key difference between internal and external tooth lock washers?
Internal tooth lock washers, like those from binifiMux, have teeth pointing inward, typically used for smaller fastener heads or when a flush appearance is desired. External tooth lock washers, such as those by MroMax, feature teeth extending outward, providing a broader grip and often preferred for larger bolt heads or maximum locking force.
When should 304 stainless steel tooth lock washers be chosen over carbon steel options?
304 stainless steel tooth lock washers, exemplified by Vifmy's offerings, are preferred in environments prone to moisture, chemicals, or high humidity, where corrosion resistance is paramount. Carbon steel versions with black oxide finishes are suitable for less corrosive indoor applications where high strength is needed but extreme rust prevention is not the primary concern.
How do tooth lock washers prevent loosening due to vibration?
The teeth of the washer embed into the fastened material and the underside of the fastener head. This mechanical interlock creates resistance to rotation and maintains tension, effectively preventing the fastener from backing out under vibrational stress.
Are all tooth lock washers suitable for high-vibration environments?
While all tooth lock washers are designed to resist loosening, some, like the MroMax external tooth washers, are explicitly marketed and engineered for high-vibration environments. The material, tooth design, and specific manufacturing processes can influence their performance in extremely dynamic conditions, so checking product specifications is advisable.