Best M4 Lock Washers in 2026

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Products including all types of screws, rivets, socket head cap screws, flange bolts and nuts, concrete anchors, split pins, stainless steel fasteners, brackets, U-bolts; in fact virtually anything!

GALVANIZED STAINLESS STEEL: These lock and flat washers provide excellent protection and security for nuts and bolts. They are made with galvanized stainless steel for long-term use and outstanding durability.

VERSATILE & COMPATIBLE: These assorted washers come in multiple sizes to fit all your screws, nuts, and bolts. Each washer features a solid bearing surface to prevent the nut or bolt head from tearing through the material.

OPTIMAL SURFACE AREA: Each stainless-steel flat or lock washer easily deflects the screw or bolt load, spreading the weight evenly for a secure and sure fit. These washers for screws and bolts are ideal for use at home or in the workshop.

【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.

Commonly used in applications using a bolt or a screw where two pieces are being joined together

Split ends grip the material surface to prevent loosening during vibration

18-8 Stainless Steel finish for good corrosion resistance

Quality and strong standard type 400 series stainless steel

Each pack is professionally heat sealed and labeled by Marine Bolt Supply

Offered in convenient small or large quantity packs

【✔】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

√【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.

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.

【✔】High Quality 304 Stainless Steel Internal Tooth Starlock Washers Kit

【✔】Made of 304 Stainless Steel Material, Very Good Corrosion Resistance, It Can Be Used in a Humid Environment

【✔】Set Includes 7 Most Used Sizes: M3 M4 M5 M6 M8 M10 M12【 Please See Picture 2 for Specific Dimensional Size】

♛ 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 Includes】: It contains 100pcs 8mm x 25mm large fender washers, thickness are 1.2mm. Sufficient quantities can satisfy almost all your needs in daily life and work.

♛【High Quality Material】: All the flat washers are made of high quality 304 stainless steel, which has good performance of high hardness, corrosion resistance and rust resistance even in bad environment like high temperature, cold weather, and high humidity areas, ensures long service time.

♛【Function and Use】: Flat washers are well made, with smooth and shiny surface, which are mainly used to reduce pressure and friction, prevent leakage, isolate, loosening or disperse pressure. Suitable for indoor and outdoor usage.

HIGH QUALITY STAINLESS: These 100 Piece Lock Washers are 100% 18-8 (304) Stainless Steel which is one of the highest forms of corrosion resistant steel, making it last longer than other hardware on the market today.

WASHERS THAT YOU CAN DEPEND ON: Our hardware is very strong and is great for both indoor and outdoor use. The stainless steel is superior to regular steel and provides excellent rust resistance in water applications.

GREAT TO KEEP AROUND: Persberg hardware is great to have around for use in wood and wet environments. Persberg washers are the highest quality available on the market and we stand by our claim 100%. They are strong, corrosion resistant and will support all of your projects.

→Product: Starlock Washer Assortment Kit;

→Material: 304 Stainless Steel; →Main Color: Silver;

→Package: 220pcs x Starlock Washers

Package Includes: 100 PCS M8 Metric Split Lock Washer

Specifications: outside diameter 13.1mm; inside diameter 8.7mm; compressed height 2.2mm; uncompressed height 5.25mm

Lock washers are commonly used in any application using a bolt where two pieces are being drawn together

Dimensions: OD = .47", ID = .256" Thickness = .028"

Quality and strong standard type 400 series stainless steel

Each pack is professionally heat sealed and labeled by Marine Bolt Supply

➤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

304 stainless steel Inner diameter 1/4 inch split lock washer.

For use with 1/4 inch bolts and machine screws.

Great corrosion resistance for outside applications.

MATERIAL: Assorted washers are manufactured with 304 stainless steel, washer set has the benefits of corrosion resistance, and good wear resistance, and a high level of hardness, which can ensure durability, even in worst weather conditions like rain, humidity, and high temperature

DIMENSIONS: Stainless steel washers comes in 15 different sizes: M3(15x0.8mm), M4(20x1.2mm), M4(25x1.5mm), M5(20x1.2mm), M5(25x1.4mm), M6(20x1.5mm), M6(25x1.5mm), M6(30x1.5mm), M8(20x1.4mm), M8(25x1.5mm), M8(30x1.5mm), M10(20x1.5mm), M10(25x1.5mm), M10(30x1.5mm), M12(24x1.5mm)

QUANTITY: Washers for bolts come in 15 sizes and 225 pieces overall, & each stainless-steel finish washers have a different purpose, and all products require different sizes of the washer. It comes with zip lock to prevent mixing up the sizes in a transparent box

√【Kindroufly Combination】: M3 M4 M5 M6 M8 M10 M12, total 15 sizes 270 pieces 304 stainless steel fender washers in a solid transparent storage box , different sizes and enough quantities can meet your different daily long time using.

√【High Quality Stainless】: Kindroufly large 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.

√【Large Fender Washers Function】: Fender washers are commonly used to prevent nuts from loosening. Our fender 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.

【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.

DIMENSIONS: Inside Diameter: 1/2", Outside Diameter: 7/8", Pack of 100, 304 stainless steel.

STAINLESS STEEL: Made from stainless steel for superior corrosion resistance, there're strong and not easy to deform or slip.

LOOSENING PREVENTION: The spring washer offers axial flexibility that's intended to protect fastened assemblies against loosening from vibration.

Note Size(Appr.): Metric flat washer assortment sets. M6 stands for the inside diameter of washer, means 6mm (1mm=.039 inch) in I.D. ALL washers are SAME thickness(1.5mm), and All washers with a wider outside diameter(25mm) Note Inside Diameter is the hole diameter, outside diameter is the round diameter.

Fast and Easy Use: Crush washers are round and flat with hole. Note the space between the lock nut and nut (1.5mm Thickness). All screws depends on the inside diameter. that means M4 washer fit with M4 screws/bolt shanks.

Multi-purpose Application: Commonly used in household. with threaded bolts, screws, nuts and flat finishing washers to tie together to prevent through. Build and repair furniture, digital products. and so on.

1141 Pieces - Inch & Metric Stainless Steel Hex Nut, Lock Washer and Flat Washer Assortment Kit!

1/4", 5/16", 3/8" 1/2", M6, M8, M10, M12 Diameters Included

Includes: Durham 24 Hole Steel Compartment Tray (Made USA) Dim: 13-3/8"x9-1/4"x2"

High Quality 7 Kinds Metric M3 M4 M5 M6 M8 M10 M12 Stainless Steel Starlock Push on Washers Assortment kit total 350Pieces

Starlock Washer;External Push Rings; Push On Washers;Speed Clips;Push Nuts for Unthreaded Shafts

Material:304 stainless steel;304 stainless steel have good chemical resistance and may be mildly magnetic

Nord-Lock wedge-locking washers are made for use with 3/8 inch stainless steel bolts and/or nuts.

Each pack contains 10 glued pairs of washers.

Applications for Nord-Lock Stainless Steel Washers include general salt water applications, pumps, chloride applications, heat exchangers, nuclear, desalination, food processing, and medical equipment.

Package Included: 100 x Split Lock Washers. Inner Dia: 0.39" / 10mm; Outer Dia: 0.63" / 16mm.

Split Lock washers apply greater bolt tension per unit of applied torque as well as a hardened bearing surface adding to a more uniform torque control. 

These lock washers resist loosening caused by vibration and corrosion.

WHAT YOU GET: 100 stainless steel #8x3/8" Spring Lock Washers ideal for use in sheet metal and wet environments with very high form corrosion resistance in 304 material

304 MATERIAL: Our Spring Lock Washers are made of 304 stainless steel, which is longer lasting than other hardware on the market and will last longer in harsh environments such as high temperature, low temperature and high humidity.

WIDELY USED: Our Spring Lock Washers can be used to fix bolts with diameter smaller than the hole of the washer, suitable for general industry such as indoor decoration, outdoor construction, electrical repair and furniture repair.

Material: Stainless Steel. Size Details: 12.5cm x 6.5cm x 2.2cm/4.92" x 2.56" x 0.87" (Approx.)

Made of high quality stainless steel material, the lock washer is anti-rust and durable to use.

The length of the product is about 12.5cm, the width is about 6.5cm, and the height is about 2.2cm.

Material: Our Sealing Gasket Is Made Of 304 Stainless Steel And Epdm Rubber, Durable And Long Life With Good Rust Resistance, You Do Not Have To Feel Frustrated By Rust

Package Quantity: Our Products Are Strictly Controlled By The Quantity Of Each Package, And Packed In A Strong And Durable Box, You Do Not Have To Worry About Receiving A Broken Package And The Number Of Packages Does Not Match The Actual

Features: The Sealing Washer Is Rubber On One Side And Metal On The Other Side Of The Washer. Suitable For Use In Metal Plates, The Rubber Helps To Solve The Problem Of Vibration Noise, The Gasket Helps To Improve The Friction Of The Screw To Enhance The Sturdiness, They Are Good Helpers For Your Work.