NEO TOOLS Copper Washer Assortment Kit, 534 Pieces, 5-22 mm ID, Sealing Gaskets for Automotive, Marine, Hydraulic, Plumbing, Industrial

When you're under a vehicle changing oil, the last thing you want is a leaking drain plug because the old copper washer gave out. This 534-piece copper washer assortment from NEO TOOLS ensures you always have the right size sealing gasket on hand. Sourced from high-purity copper, these flat washers deliver a tight, reliable seal in high-pressure and high-temperature environments, making them a staple for mechanics, plumbers, and maintenance crews alike.

Key specifications

• Material: High-purity copper (Cu) with excellent corrosion resistance
• Washer type: Flat sealing washers
• Inner diameter range: 5 mm to 22 mm
• Outer diameter range: 9 mm to 27 mm
• Thickness range: 1 mm to 1.5 mm
• Number of pieces: 534
• Number of unique sizes: approximately 16-20
• Storage: Durable polypropylene (PP) organizer case with compartments
• Compliance: RoHS compliant

Why choose it

Copper washers are prized for their ductility and malleability, which allow them to conform to mating surfaces and create a leak-proof seal. This kit covers a broad range of metric sizes, so you can handle everything from small fuel line fittings to larger hydraulic connections. The high thermal and electrical conductivity of copper also makes these washers suitable for applications where heat dissipation or grounding is needed. The included organizer case keeps sizes sorted and easy to find, saving time on every job.

Ideal use cases

• Oil drain plugs and sump plugs on cars, trucks, and motorcycles
• Fuel line and brake line fittings
• Hydraulic system connections on agricultural and construction equipment
• Plumbing fixtures and water pumps
• General industrial sealing where a soft metal gasket is required

Good to know

Copper washers are generally single-use for critical sealing applications because they work-harden when compressed. Always replace the washer when reassembling a joint to ensure a proper seal. The melting point of copper is approximately 1085 °C (1984 °F), so these washers can withstand high temperatures far beyond typical engine or hydraulic system heat. Store the case in a dry place to prevent surface oxidation, though light tarnishing does not affect sealing performance.