came fast, looks like nice kit, have not had chance to use it.

Very Nice set of copper washers!

Excellent quality and quantity of washers

This is a yes for craft use

they stopped the leak

The 330 Pieces 12 Sizes Copper Washers assortment kit is a highly practical and versatile collection of premium copper metric flat washers designed to cater to a variety of applications. This set includes washers in 12 different sizes ranging from M5 to M20, making it suitable for a broad range of projects, from automotive repairs to plumbing, electrical, and general mechanical work. Below is a detailed review based on the features, performance, and overall value of the product.1. Design and Build QualityPremium Copper Material: These washers are made from high-quality copper, known for its corrosion resistance, durability, and excellent sealing properties. Copper is especially effective in applications where sealing is crucial, as it provides a tight, leak-proof fit. The washers are also resistant to wear, ensuring long-term performance in demanding environments.Flat Washer Design: These are flat washers, designed to distribute the load of fasteners evenly, reducing the risk of damage to surfaces and providing a secure seal. The flat, smooth finish ensures a tight fit when placed between bolts, nuts, or other fasteners, making them ideal for sealing threaded connections.Precise Manufacturing: The washers are well-manufactured with precise dimensions to ensure proper fitment for each size. The edges are smooth and free of defects, allowing for easy installation without damaging surrounding materials.2. Variety of Sizes12 Different Sizes: The 330-piece kit includes washers in 12 different sizes, ranging from M5 to M20. This wide variety ensures compatibility with a range of fasteners, including bolts, screws, and nuts, giving you flexibility for different types of projects.Common Metric Sizes: The assortment covers the most commonly used metric sizes in both residential and industrial applications. Sizes include M5, M6, M8, M10, M12, M14, M16, and M20, allowing the user to easily find the right washer for their specific need.3. Functionality and PerformanceSealing Properties: Copper washers are known for their excellent sealing properties, making them perfect for use in plumbing, fuel lines, automotive engines, and other high-pressure systems. They prevent leaks by providing a tight seal when compressed between surfaces, effectively blocking the passage of liquids, gases, or other materials.Corrosion Resistance: Copper is highly resistant to corrosion, which makes these washers especially effective for applications in wet or corrosive environments. The resistance to oxidation also ensures that the washers maintain their integrity over time and won't degrade under extreme conditions.Durable and Long-Lasting: The high-quality copper material makes these washers durable and able to withstand wear and tear. They can endure the mechanical stresses of frequent use in a variety of applications without losing their sealing ability.4. Ease of UseEasy to Identify and Use: The washers are neatly organized in a compact storage box, with each size separated into clearly labeled compartments. This makes it easy to find the exact size you need quickly, without the frustration of searching through a messy bag or container.Convenient Assortment: Having 330 washers in various sizes ensures you have plenty of stock to complete multiple projects without running out or needing to make extra purchases. This is especially helpful for anyone who frequently works on mechanical or plumbing systems and requires various sizes for different applications.Versatile Applications: These washers can be used in a variety of systems and settings, including automotive repairs, plumbing, fuel lines, water pumps, and general mechanical work. They are also useful for electrical applications, ensuring proper grounding when used as connectors.5. Value for MoneyAffordable Kit: Given the 330 pieces and the wide variety of sizes included, this kit offers excellent value for money. You get a comprehensive selection of washers for a very reasonable price, making it an economical choice for both DIY enthusiasts and professionals.Cost-Effective: Purchasing an assortment kit like this one saves you the hassle of buying washers individually. With a variety of sizes at your disposal, you are more likely to find the right washer for your needs without having to visit the hardware store multiple times.Long-Term Investment: The durability and corrosion resistance of copper washers ensure that they last for a long time, offering a reliable solution for sealing in various applications. The kit provides enough washers to last through many projects, making it a solid long-term investment.6. Customer FeedbackPositive Reviews on Quality: Customers have praised the high quality of the copper used in the washers, noting that they are highly effective at sealing and resistant to wear. The material provides a great seal even under pressure, which is crucial for many types of work, such as automotive and plumbing repairs.Convenient Assortment: Many users have highlighted the convenience of having an assortment of sizes readily available. The well-organized packaging helps users find the right size quickly, making the product ideal for both occasional DIY use and more frequent professional tasks.Reliable Sealing: The washers have been appreciated for their ability to provide a tight, leak-proof seal. Several customers reported using these washers in critical applications, like fuel lines, where leak prevention is essential, and found them to work reliably.ConclusionThe 330 Pieces 12 Sizes Copper Washers Assortment Kit is an excellent product for anyone who frequently works with fasteners, plumbing, automotive, or mechanical systems. Made from premium copper, these washers offer superior corrosion resistance and sealing properties, making them perfect for applications requiring reliable leak prevention.The kit provides a wide range of sizes (from M5 to M20), ensuring that you’ll have the right washer for almost any job. With a total of 330 washers neatly organized in a convenient storage case, this product offers exceptional value for money, making it a great investment for both DIY enthusiasts and professionals. Whether you're working on automotive repairs, plumbing, or general mechanical tasks, the CBTLYSK copper washers deliver long-lasting performance and reliability.

I was a bit concerned when I ordered these copper washers. You use copper washers when you want a slightly more malleable washer to have a bit of "give" to ensure a proper seal and tightening regime in an uneven location. However, the malleability is a critical factor. To soft and the washer is useless. Not soft enough and you might as well order steel. These can also be used when you're in a harsh environment and expect oxidation - I did not test for that.I decided to test these on "rough" metal surfaces to see how tightly they would seal with a nut compared to a steel washer. I am pleased to say that they actually did quite a bit better than a stainless washer of the same size under the same torque. What I did was looked for a roughed up piece of u-shaped metal rod in my shop, drilled to identically sized holes allowing them to punch through unevenly and not smoothly. I then attempted to seal each with a screw/nut and a top and bottom washer. After screwing to hand tight, I torqued a 1/2 inch bolt to approximately 50 lb-ft, slightly less than is recommended. I flooded the top of the steel rod. The copper washers did not leak, the steel only slightly. I reversed the bolts in the holes and the same result. Of course, this is far from scientific, but it did give me an indication that what I hoped may be true was happening.Worked as expected - 4 stars.************** VINE Notice ************************Even though I have been given this product as part of a VINE review by Amazon, my reviews are honest and not influenced by receiving the product. Quite frankly, I could buy this if I wanted it, and I am doing these reviews for fun. I am a 65 year old guy and have appreciated the very clear and detailed reviews on Amazon. I started leaving my own and was selected to give these for products that I wanted to look into. But I will call a dog a dog.*************** Explanation of Rating System *************************My rating system.1 star - terrible. I wouldn't consider buying it.2 stars - marginal at best. Doesn't meet the minimum requirements or quality to be useful. Buy it at your own risk.3 stars - average. Meets the quality and requirements for a product of this type but is nothing out of the ordinary. If the price is good, I'd probably buy it.4 stars - better than average. Exceeds the typical quality of a product of this type and has a few extra features not usually found on other products of this type. I'd buy it.5 stars - exceptional - far exceeds the quality of products of this type. Hard to beat the quality and features included. Best value for the money. I wouldn't hesitate to buy it.

These copper washers are fantastic! I used them for my car’s oil drain plug, and they provided a perfect, leak-free seal. The quality is exceptional—they’re sturdy and well-machined. The assortment of sizes is really convenient and saved me a lot of time. Great product for anyone doing maintenance or repairs.