Best M4 Lock Washers in 2026

Daisy
Last Updated: Jul 17, 2026

At a Glance: Our Top Picks for M4 Lock Washers

800 Pcs 304 Stainless Steel Flat Washers for Screws Bolts, Fender Washers Assortment Set, Assorted Hardware Lock Metal Washers Kit (9 Sizes-M2 M2.5 M3 M4 M5 M6 M8 M10 M12) for Home, Factories etc YLYL
#TOP1
800 Pcs 304 Stainless Steel Flat Washers For
9.7
PM SCORE
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
#TOP2
Hilitchi 300-Pcs [8-Size] 304 Stainless Steel External Tooth
9.6
PM SCORE
800 Pieces 304 Stainless Steel Flat Washers, Fender Washers, Kindroufly 9 Sizes Stainless Steel Washers, Lock Metal Washers Assortment Kit (M2 M2.5 M3 M4 M5 M6 M8 M10 M12)
#TOP3
800 Pieces 304 Stainless Steel Flat Washers, Fender
9.6
PM SCORE

* PickSmartly editors independently research, review, and endorse the top products through comprehensive data analysis. We may earn a commission for qualifying purchases made through our product links.

Summary of the Best M4 Lock Washers of 2026

Market Overview
M4 Lock Washers Reviewed
  • Reviews Analyzed: 7825 Items
  • PM Avg. Rating: 8.6 / 10
16 Products Evaluated
  • Highest Price: $12.99
  • Lowest Price: $7.99
  • Avg. Price: $10.36

800 Pcs 304 Stainless Steel Flat Washers For Screws Bolts, Fender Washers Assortment Set, Assorted Hardware Lock Metal Washers Kit (9 Sizes-M2 M2.5 M3 M4 M5 M6 M8 M10 M12) For Home, Factories Etc Ylyl

YLYL
ZHUYU009
5.04 X 2.67 X 0.90 Inches
11.00 ounces
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Ylyl Direct 9.68

Features

【800 Pcs Washers for Screws】800 Pcs stainless steel flat washers for screws bolts, 9 different sizes M2(210 Pcs) M2.5(200 Pcs) M3(100 Pcs) M4(100 Pcs) M5(70 Pcs)M6(40 Pcs ) M8(50 Pcs ) M10(20 Pcs ) M12(10 Pcs ),Total:800 pcs / 9 different sizes fender washers assortment set kit can meet your different needs.

【Top 304 Stainless Steel】Our assorted hardware Lock metal washers, is made of top 304 stainless steel which has the advantages of high hardness, well wear-resistance, corrosion resistance and rust resistance. Which can ensure long time using even in bad environment like high temperature, cold weather, and high humidity areas.

【Widely Application】Fender washers assortment set kit, perfect for interior decoration, outdoor construction, electrical maintenance and furniture repair, The flat washers could be used for fixing bolts with smaller diameter than the hole of washers.

【Easy Storage】All stainless steel flat washers for screws bolts are packed in a sturdy Transparent Plastic case, Clear and Easy to Use Storage Box Use 9 grids to distinguish 9 sizes, with specification label, for your use simple and clear every time.

【SATISFACTION GUARANTEED】Our team is committed to providing every customer with good assorted hardware lock metal washers and satisfactory service. If there are any problems with our fender washers assortment set kit, contact us and we would be very happy to solve your problems. Be sure to Add to Cart.

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
HDPWX-300
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hilitchi 9.88

Features

【✔】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.

800 Pieces 304 Stainless Steel Flat Washers, Fender Washers, Kindroufly 9 Sizes Stainless Steel Washers, Lock Metal Washers Assortment Kit (M2 M2.5 M3 M4 M5 M6 M8 M10 M12)

KINDROUFLY
KINDROUFLY---FLAT---WASHER
5.20 X 3.60 X 0.72 Inches
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
KINDROUFLY 9.88

Features

√【Kindroufly Combination】: M2 (200 pieces), M2.5 (200 pieces), M3 (100 pieces), M4 (100 pieces), M5 (72 pieces), M6 (50 pieces), M8 (50 pieces), M10 (20 pieces), M12 (8 pieces), total 9 sizes 800pieces, different sizes and enough quantities can meet your different daily needs.

√【High Quality Stainless】: Kindroufly fender washers are made of 304 stainless steel, which have smooth surface, high strength, not easy to deform, corrosion resistance and rust resistance, can ensure a long time using in bad environment like high temperature, cold weather, and high humidity areas.

√【Fender Washers Function】: Flat washers are commonly used to prevent nuts from loosening. Our flat washers are well made, with smooth and shiny surface, highly compatible with screws, nuts and bolts of same sizes and feature solid bearing surface to prevent nut/bolt head from tearing through material.

√【Multi-functional Storage Box】: All Kindroufly 800 pieces 9 sizes stainless steel flat washers are packed in a solid transparent storage box. we put 9 sizes flat washers in 10 grids , each size are marked with a clear label. It is very convenient for you to choose size, easy to carry and store, which can save your time and energy.

√【Widely Applications】: Kindroufly 9 sizes stainless steel washers, lock metal washers, fender washers assortment kit are widely used for interior decoration, outdoor construction, electrical maintenance and furniture repair. If you have any questions about our products, welcome your inquiry and we will solve the problem for you in time.

900 Pieces Black Zinc Flat Washers For Screws Bolts, Helifouner Flat Washers Assorted Kit, Flat Washers, Metric Washers, Lock Metal Washers (M2 M2.5 M3 M4 M5 M6 M8 M10 M12)

HELIFOUNER
HELIFOUNER---FLAT---WASHER
5.00 X 3.00 X 0.72 inches
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
HELIFOUNER 9.89

Features

【Sizes】M2 M2.5 M3 M4 M5 M6 M8 M10 M12, total 900 pieces/9 sizes of the most commonly used black zinc washers, flat washers, metal washers in a plastic case, different size can satisfy your different needs.

【Design】Flat washers, metric washers, metal 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】Black zinc plated steel, 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.

【Package Included】900 pieces 9 sizes in total, package in a durable transparent box with label. It is easy to distinguish the size of the product, you can choose the suitable one to meet all your needs.

【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.

Qteatak 320Pcs Lock Washers 304 Stainless Steel Internal Star Washer, 8 Sizes Tooth Washer Wave Spring Washer Assortment Kit M2.5 M3 M4 M5 M6 M8 M10 M12, Silver

QTEATAK
JF-0091
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
JianFeng Store 9.86

Features

Internal Tooth Star Lock Washers: High Quality Stainless Steel External Tooth Star Lock Washers Set of 320 pcs, includes the most commonly used 8 sizes: M2.5: 50 pcs / M3: 50 pcs / M4: 50 pcs / M5: 50 pcs / M6: 50 pcs / M8: 30 pcs / M10: 20 pcs / M12: 20 pcs.

Features: Internal Tooth Lock Washer Star 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.

Material: Made of high-quality 304 stainless steel environmentally friendly materials, high strength (not easy to deform), wear-resistant, corrosion-resistant, rust-resistant and oxidation-resistant. All gaskets will be packaged in a sturdy clear plastic box that can be used in a storage box.

Applications: Widely used in a variety of screw fastening applications, ideal for electrical connections in household and commercial appliances, automobiles and ships.

100% SERVICE: We Promise the Premium Quality and the Best Service, If You are Not Completely Satisfied with Your Purchase Simply Let us Know.

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
HDPHX-400
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hilitchi 9.88

Features

【✔】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.

Qteatak 320Pcs Stainless External Multi-Tooth Star Lock Washers Assortment Set-304 Stainless Steel, 8 Size (M2.5 M3 M4 M5 M6 M8 M10 M12)

QTEATAK
JF-0090
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
JianFeng Store 9.86

Features

External Tooth Star Lock Washers: High Quality Stainless Steel External Tooth Star Lock Washers Set of 320 pcs, includes the most commonly used 8 sizes: M2.5: 50 pcs / M3: 50 pcs / M4: 50 pcs / M5: 50 pcs / M6: 50 pcs / M8: 30 pcs / M10: 20 pcs / M12: 20 pcs.

Features: Internal Tooth Lock Washer Star 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.

Material: Made of high-quality 304 stainless steel environmentally friendly materials, high strength (not easy to deform), wear-resistant, corrosion-resistant, rust-resistant and oxidation-resistant. All gaskets will be packaged in a sturdy clear plastic box that can be used in a storage box.

Applications: Widely used in a variety of screw fastening applications, ideal for electrical connections in household and commercial appliances, automobiles and ships.

100% SERVICE: We Promise the Premium Quality and the Best Service, If You are Not Completely Satisfied with Your Purchase Simply Let us Know.

#TOP8

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
HLFW-640
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hilitchi 9.88

Features

♛ 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

Hilitchi 300-Pcs 304 Stainless Steel External Tooth Star Lock Washers Assortment Kit - Included: M2.5 M3 M4 M5 M6 M8 M10 M12

HILITCHI
HETW-300
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hilitchi 9.88

Features

♛ High Quality Stainless Steel External Tooth Star Lock Washers Set

♛ Set Includes 8 Most Used Sizes: M2.5 M3 M4 M5 M6 M8 M10 M12

♛ 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

♛ Perfect for electrical connections on household and commercial appliances, automotive and marine uses in which the power source has a threaded/bolt-type connection

Qteatak 260 Pcs 7-Size 304 Stainless Steel Flat Washer & Lock Washer Assortment Set (Size Included: M2.5 M3 M4 M5 M6 M8 M10)

QTEATAK
JF0003
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
JianFeng Store 9.86

Features

1. 304 Stainless Steel Spring Lock Washers Set,Good Corrosion Resistance, It Can Be Used in a Humid Environment.

2. 7 Most Used Sizes: M2.5 M3 M4 M5 M6 M8 M10, Flat & Lock

3. 260 Pieces,Packed in A Sturdy Transparent Plastic Case

4. As a Reliable, Responsible Professional Producer, We Will Not Cut Corners on the Quality of Products.

5. NOTE Cause of the Small Size, Please Keep it Properly, Avoid to Play by Children and Lead to Accidental Swallow or other Dangers!

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
LH2262
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Lena Home Tools 9.89

Features

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.

Oiiki 260Pcs 9 Sizes Internal Tooth Washers, Push On Speed Clips Fasteners Kit, 65 Mn Steel Black Oxide Finish Star Lock Washers (9 Sizes)

OIIKI
LH2262T2-CA
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Lena Home Tools 9.88

Features

Internal tooth star locking 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: 260pcs 9sizes of M2, M2.5, M3x10, M4x12, M5x14 each size 40 pieces; M6x16, M8x18, M10x20, M12x25 each size 15 pieces, 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.

Cseao 235Pcs[8 Sizes] Black Starlock Internal Tooth Lock Washers Assortment Kit, M2/ M3/ M4/ M5/ M6/ M8/ M10/ M12

CSEAO
43398-30050
0.51 Pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
cSeao 9.76

Features

☞ Material: 65Mn Steel

☞ Package: 235pcs x Starlock Washer in one storage box

☞ Main Color: Black;

☞ Include sizes: M2, M3 x 9mm, M4 x 12mm, M5 x 12mm, M6 x 16mm, M8 x 18mm, M10 x 20mm, M12 x 25mm

☞ Product name: Internal Tooth Washers

#TOP14

304 Stainless Steel Flat Washers Assortment Set,Socell 700Pcs 9 Sizes Lock Metal Flat Washers For Bolt Screws Hardware Assortment Kit For Home Decoration, Factories Repair, Kitchens(M2 - M12)

SOCELL
SO201019001
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Socell Shop 8.51

Features

➤SOCELL stainless washers include :M2 M2.5 M3 M4 M5 M6 M8 M10 M12 flat washers.These sizes are often needed.

➤SOCELL stainless steel washers for screws contain 700pieces flat washers and a storage box for quick and easy use.

➤Widely Application: Perfect for electrical connections on household and commercial appliances, automotive and marine uses in which the power source has a threaded/bolt-type connection

➤These metal washers and stainless steel washers are made by Socell have good quality and high durability.The flat washers can effectively disperse the pressure generated by the fastener head,by increasing the contact area, parts can be protected from damage,and prevent loose connection between fasteners.

➤If you are not satisfied with the product can be returned,please contact us by email,we will provide you with the best quality after-sales service.

900 Pieces 304 Stainless Steel Spring Lock Washers For Screws Bolts, Helifouner Lock Washers Assorted Kit, Stainless Steel Lock Washers, Lock Metal Washers (M2 M2.5 M3 M4 M5 M6 M8 M10 M12)

HELIFOUNER
HELIFOUNER---LOCK---WASHER
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
HELIFOUNER 9.89

Features

【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.

#TOP16

Mogen886 260Pcs M2-M12 Steel Nut Locking Star Washers Bearing Clamps Fastener Washers Set Kit Repair Tools Black

MOGEN886
SNMK72WXR42D3K703OXISL0
0.43 Pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
TRENTON 7.40

Features

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.

Top 10 lock washers Brands on Amazon

Here is the list of top-rated brands that were evaluated by PM.

Brand Count
Hilitchi 4
Qteatak 3
Helifouner 2
Oiiki 2
Cseao 1
Kindroufly 1
Mogen886 1
Socell 1
Ylyl 1

Top 10 lock washers Brands Pie Chart


We've carried out a comprehensive analysis of 7,825 reviews on lock washers, using our selection criteria to identify the best options in the fasteners. Our findings reveal that most customers typically select lock washers priced around $10.36, with top brands including wensilon, hilitchi, helifouner, qteatak, busy-corner, persberg and pzrt and the hillman group

Our team of expert editors reviewed these high-quality items and handpicked the top 16 lock washers for your consideration. We've also done extensive research on numerous sellers, identifying the best ones in the fasteners category. These include wensilong, hilitchi, helifouner, jianfeng store, busy-corner and pzrt and amazon.com .

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