A crush washer is used in between the fastener and mating surface to seal the leak. It is mainly made of aluminum and copper.
But, aluminum vs copper crush washer, how do they differ? Copper crush washers are more durable than aluminum crush washers. Also, copper has a higher melting point in terms of heat resistance, making it better than aluminum. Additionally, aluminum is more corrosion-resistant and lightweight but costlier than copper.
However, this is just a glimpse of discussion. In this comparison guide, I will compare both washers side by side and their usage. After reading this, you can make an informed decision about which one is perfect for your usage. Let’s break down the sides.

Aluminum vs Copper Crush Washer: A Quick Comparison
Here is a quick comparison of aluminum vs copper crush if you are in a hurry before purchasing one. Please check these.
Comparison Aspects | Aluminum Crush Washer | Copper Crush Washer |
---|---|---|
Strength and Durability | Less strong than copper | Stronger than aluminum |
Resistance to Corrosion | More resilient to corrosion | Less corrosion resistant than alloy |
Heat Resistance | Low melting temperature (660.3°C) | Higher melting temperature point (1,085°C) |
Weight | Lightweight | Heavier than aluminum |
Usages | Lightweight applications like magnetic oil drain plugs, banjo fitting like brake calipers, fuel filters, hydraulic clutch systems, power steering fluid lines, etc. | High-temperature applications like cylinder heads, fuel injectors, fuel fitting, hydraulic systems, etc. |
Cost | Costlier | Less expensive |
Aluminum vs Copper Crush Washer: Side-By-Side Comparison
You have a glimpse of the differences between aluminum and copper crush washers. Now let’s compare both side by side to get into the insight of both crush washers in detail.
Strength and Durability
In terms of strength, the copper is a clever winner here. The tensile strength of copper is 380 MPa or 55,114 psi. On the other hand, the tensile strength of aluminum is up to 200 MPa, or 29,000 psi.
That means copper can hold up to 55,000 pounds per square inch of pressure, whereas aluminum can hold up to 29,000 pounds per square inch of pressure.
Resistance to Corrosion
Aluminum is more resistant to corrosion than copper. Research has shown that the rate of corrosion of copper is two times higher than aluminum at room temperature.
As a result, they are a highly appropriate choice for outer applications that come to air frequently. For example, in the outer oil drain plug-in vehicles, aluminum crush washers are perfect to use.
However, copper also has decent corrosion capability as well.
Heat Resistance
In terms of heat resistance, copper is far ahead of aluminum. The melting point of copper is 1084°C (1,983°F). On the other hand, the melting temperature of aluminum is 660°C (1,220°F).
That means copper will start to melt when the temperature reaches 1,084°C. But aluminum will start to melt at 660°C (1,220°F).
Copper has a higher melting point because it has a higher density. The higher density makes copper highly resistant to high temperatures.
So, when it’s about high-temperature application areas like engine cylinder heads, a copper crush washer should be the optimal choice. It will prevent damage to the engine from brake fluid.
Weight
In terms of weight, aluminum has a lighter weight than copper. This is because, physically, aluminum has low density.
So, you can easily fit them in the usage area like oil filter pan plug, fuel filter joints, power steering fluid line, etc.
Although both copper and aluminum crush washers give excellent fitting advantages, aluminum does a slightly better performance here. Due to its lower physical density and weight, aluminum is crushed more easily and gives an excellent sealant feature.
Usages
As I mentioned earlier, aluminum crush washers are more likely to be used in low-temperature areas. Their physical flexibility and ease of usage allow them to be used in Lightweight applications like-
- Magnetic oil drain plugs
- Banjo fitting like brake calipers to prevent brake fluid on tires
- Fuel filters, hydraulic clutch systems, power steering fluid lines, etc.
On the other hand, copper crush washers can also be used in such application areas as well. But you will want to use them in high-temperature cases like engine cylinder joints for extreme sealant.
Note: For a simple understanding of the better use of aluminum and copper crush washers, you can follow the tips below.
- If you have two steel parts to join, the copper crush washer is better.
- But, if there is even a single part of aluminum, aluminum crush washers will ensure the best result.
Cost
The cost is a big factor in many cases. But in the case of crush washers, this doesn’t impact a lot, yet you may consider the cost.
Aluminum is a little bit costlier than copper crush washers. You will find a set of aluminum crush washers at around $18 to $20.
On the other hand, copper crush washers are a little less expensive than aluminum crush washers. You need to spend around $12 to $16 for a set of copper crush washer sets.
Advantages of Aluminum and Copper Crush Washers
Let’s summarize the advantages of both aluminum and copper crush washers.
Advantages of Aluminum Crush Washer
- Aluminum crush washers are lightweight
- They are flexible and easy to use
- They are more corrosion-resistant
- Durable enough for its desired usage for sealing, like in banjo fittings and magnetic oil drain plugs
Advantages of Copper Crush Washers
- Copper crush washers are highly durable
- They are reliable for both low-temperature and high-temperature areas for fastener sealing
- They are more heat-resistant
- Copper crush washers are less expensive than aluminum crush washers
Disadvantages of Aluminum and Copper Crush Washer
Here are some limitations you should keep in mind for both aluminum and copper crush washers.
Limitations of Aluminum Crush Washers
- Not highly resistant to heat like copper
- Not applicable for high-temperature usage
- They are a little more costlier than copper crush washers
Limitations of Copper Crush Washers
- Copper crush washers are a little heavier than aluminum crush washers
- They are less corrosion-resistant than aluminum crush washers
Final Verdict: Which One Will You Choose?
So, aluminum vs copper crush washer, which one should you choose? To be specific, both are excellent washers and can withstand in most environments. But, if you particularly need high-temperature, withstanding capable crush washers, copper ones are to choose from.
On the other hand, your sealing application areas may not need a highly temperature-resistant crush washer. Also, you might need more corrosion resistance. In this case, choose aluminum crush washers.