Bevel gears that are subjected to corrosion and lightly loaded are typically made of which material?

Bevel gears that are exposed to corrosive environments and experience light loads benefit from materials that not only resist corrosion but also provide adequate strength and durability for their operating conditions. Bronze is known for its excellent corrosion resistance, particularly in marine environments and other applications where moisture is a concern. It also has good wear properties, which are advantageous in gearing applications.

Brass, while also resistant to corrosion and providing good machinability, may not be as robust as bronze in high-load applications. However, it is lighter and can be suitable for lightly loaded applications where weight savings are considered.

Duralumin, an aluminum alloy, offers high strength-to-weight ratios and is corrosion-resistant, but may not be the best choice for certain gear applications where wear resistance is a critical factor, particularly if lubrication is not continuous.

Since both bronze and brass present viable options for bevel gears under the specific conditions of corrosion and light loading, and since duralumin could also be used in some scenarios, selecting "all of these" reflects the idea that there are multiple suitable materials depending on the specific requirements of the application, including environmental factors and load considerations. Thus, it is appropriate to conclude that "all of these" materials could be suitable for the described conditions.