10Pcs DIN7603 Copper Sealing Washers M4–M10 Flat Crush Seal Ring

10Pcs DIN7603 Copper Sealing Washers – M4 to M10 Flat Crush Seal Rings

Keep your fittings leak-free with these precision-made DIN7603 copper sealing washers. Available in M4, M5, M6, M8, M9, and M10 sizes, these 1.5mm-thick flat crush washers create a reliable metal-to-metal seal on threaded connections — perfect for marine, hydraulic, automotive, and plumbing applications. Each pack contains 10 pieces of high-quality copper washers ready to handle demanding environments.

Made in Mainland China.

Key Features

• Material: Pure copper for excellent corrosion resistance and ductility
• Standard: DIN7603 specification for consistent, reliable fitment
• Sizes Available: M4, M5, M6, M8, M9, M10
• Thickness: 1.5mm uniform crush profile for a tight, leak-proof seal
• Quantity: 10 pieces per pack
• Application: Ideal for boats, engines, hydraulic lines, plumbing fittings, and drain plugs
• Reusable: Soft copper construction allows for crush-and-seal performance across multiple uses

Specifications

Why Choose Copper Sealing Washers?

Copper is the go-to material for sealing washers because it is naturally soft enough to deform and fill microscopic surface irregularities when tightened, forming an airtight and watertight seal. Unlike rubber or fibre washers, copper withstands high temperatures and pressures without degrading — making these washers an excellent choice for engine oil drains, fuel systems, and marine hardware.

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Frequently Asked Questions

Q: What sizes are included in this copper sealing washer pack?

A: These DIN7603 copper sealing washers are available in M4, M5, M6, M8, M9, and M10 thread sizes. Each pack contains 10 pieces of your selected size, all with a uniform 1.5mm thickness for consistent sealing performance.

Q: Are these copper washers suitable for boat and marine use?

A: Yes! These flat crush washers are specifically designed for demanding environments including marine (boat) fittings, hydraulic systems, engine drain plugs, and fuel line connections. Copper's natural corrosion resistance makes it an excellent choice for wet or saltwater-exposed applications.

Q: Can I reuse these copper sealing washers?

A: Copper crush washers are designed to deform slightly when torqued, creating a leak-proof seal. While they can sometimes be reused if not fully crushed, it is generally recommended to use a new washer each time to ensure the best seal integrity, especially in high-pressure or safety-critical applications.

Q: Do these washers conform to DIN7603 standards?

A: Yes, these washers are manufactured to the DIN7603 specification, which defines the dimensions and tolerances for copper and aluminium sealing washers used on threaded fittings and connectors.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.