What material are sealing caps typically made of to keep them lightweight?

Sealing caps are typically made of lightweight materials that can still provide effective sealing properties. Aluminum is often chosen for its combination of low weight, strength, and corrosion resistance. It can easily be molded or formed into the necessary shapes for sealing applications and is common in various aerospace components.

In contrast, other materials like steel tend to be heavier and less suitable for applications where weight reduction is crucial, such as in aerospace engineering. Plastic, while lightweight, may not always provide the required durability or temperature resistance. Carbon fiber, although very strong and lightweight, is often more costly and not always necessary for sealing applications compared to aluminum. Therefore, aluminum is a practical choice for sealing caps in aerospace to balance weight, cost, and performance.