Best M4 Hardware Washers in 2026

Material: 100% copper, high conductivity, corrosion resistant copper washer assortment

150PCS 15 Popular Sizes Sealing Washers Kit, great for sump plugs, water, fuel, and hydraulic fittings

150 pcs solid copper sump plug washer set. All contained in a compact and see through compartmented plastic case, convenience to use.

★『Product Type』: High quality large penny fender washers assortment set.

★『High Quality Meterial』: All the flat washers are made of 304 stainless steel, which offers good corrosion resistance in bad environment like high temperature, cold weather, and high humidity areas. They have superior rust resistance and the excellent of oxidation resistance.

★『Easy to Use』: They are very easy to install, the washer's surface are smooth can reduces friction between the fasteners, prevents leakage, isolates, prevents loosening or dispersion pressure.

❤ 1, HIGH QUALITY MATERIAL ---- High quality pure copper material, fine workmanship, smooth surface, no burr, durable, long service life, not easy to damage, the material itself luster can be preserved for 10 years and 20 years as new.

❤ 2, WIDE 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

❤ 3, EASY TO USE ---- Sturdy and durable, great corrosion resistance for outside applications, easy to install. Flat washers are used to support and spread the load across the baring area of the bolt and nut to prevent pull through

√【Kindroufly Combination】: M5 M6 M8 M10 M12 M14 M16 M20, total 11 sizes 320 pieces copper sealing washers, different sizes and enough quantities can meet your different daily needs.

√【High Quality Copper】: Kindroufly copper washers are high quality copper material, which have smooth surface, wear resistance, corrosion resistance and rust resistance, can ensure a long time using in bad environment like high temperature, cold weather, and high humidity areas.

√【Copper Washers Function】: High conductivity, corrosion resistant copper material provides a tighter seal and greater heat endurance than steel and rubber washers, and play the role of protection and stability Our copper washers are well made, with smooth and shiny surface, highly compatible with screws, nuts and bolts of same sizes.

Product Name: Copper Washer; Inner Diameter: 10mm/0.39" Outer Diameter: 14mm/0.55"; Thickness: 1.5mm/0.06"

Copper Provides a Tighter Seal and Greater Heat Endurance than Steel and Rubber Washers.

Max Operation temperature: 350C Max Operation pressure:16MPa Melting point: 1083C

1. Quantity: 100pcs/set heavy duty

2. Size: 8mm inner diameter, 16mm outer diameter, 1.6mm thickness

3. These 100 Piece Flat Washers are 100% 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.

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.

Flat washer provides a bearing surface for fastener load distribution or acts as a spacer

Steel is often used in applications where strength is the primary consideration

Zinc plating resists corrosion and has a reflective appearance