Which technician correctly states that a helical gear is stronger than a spur gear?

A helical gear is indeed stronger than a spur gear largely due to its design and the way the gear teeth come into contact. Helical gears have teeth that are cut at an angle to the axis of the gear, allowing for gradual engagement between the teeth. This design leads to a larger surface area in contact when the gears mesh, distributing the load more evenly across the teeth and reducing the likelihood of wear or failure.

In contrast, spur gears have teeth that are straight and parallel to the axis, which means they engage abruptly. This can lead to a higher concentration of stress at the point of contact, making them more prone to wear and potential failure under high loads.

Thus, the strength of helical gears makes them particularly suited for applications requiring higher torque capacity and smoother operation, affirming the statement made by Technician A regarding the comparative strength of helical gears versus spur gears.