Are aluminum pulleys better than steel

Customers often ask me questions like this, and there is no standard answer to this question.

However, we can compare the questions based on cost-effectiveness and practicality.  Typically, small timing belt pulleys with aluminum material have obvious advantages over iron materials. Aluminum is lightweight and easy to process, so basically 90% of timing belt pulleys are made of aluminum alloy.

• According to San Min Gears’ statistics from 2005 to 2020, for timing belt pulleys with a diameter below 30mm, 89.5% of them are made of aluminum alloy, 8% are made of brass, 2% are made of stainless steel, and only 0.5% are made of steel. Therefore, the conclusion is that aluminum alloy has overwhelming advantages in small-sized timing belt pulleys.

However, the advantages of aluminum alloy decrease in timing belt pulleys with a diameter above 30mm and up to 100mm.

• According to San Min Gears’ statistics, for timing belt pulleys with a diameter above 30mm and up to 100mm from 2005 to 2020, 72.8% of them are made of aluminum alloy, 5% are made of POM (polyoxymethylene), 2% are made of stainless steel, and only 20.2% are made of steel. Therefore, it can be concluded that the advantage of aluminum alloy diminishes as the diameter increases. This is due to the cost of materials. When compared with the same-sized cast iron material, aluminum alloy loses its unique advantage.

For timing belt pulleys above 100mm, the advantages of cast iron are very prominent. Although aluminum alloy can also be molded and cast to reduce weight, when the costs are compared for the same size, the advantages of cast iron are evident.

• However, according to San Min Gears’ data from 2005 to 2020, for timing belt pulleys above 100mm, 51.4% of them are made of aluminum alloy, and 48.6% are made of cast iron. Although cast iron has cost advantages, it lacks the advantages of lightweight and rust prevention that aluminum alloy offers in special equipment.

We usually provide engineers with recommendations based on the product characteristics when designing timing belt pulleys and timing belts:

1.For precision and lightweight requirements, aluminum alloy should be considered first.

2. For large-sized pulleys that aim to save materials without considering rusting, cast iron is preferred.

3. For special occasions with high rust prevention requirements, stainless steel should be prioritized, followed by aluminum alloy pulleys with surface oxidation.