For solid shafts and hollow shafts with the same outer diameter, does the hollow shaft have higher strength?

Hollow shafts are lightweight, experience minimal deformation when heated, and are inexpensive

Of course, it’s a solid shaft, but the difference isn’t significant; whereas a hollow shaft is lighter in weight.

Industrial equipment relies on shafts for proper operation, and there are many different types of such shafts. For example, hollow shafts and solid shafts represent the two most distinct categories. As for which of them is more practical, it Of course needs to be determined through comparison. Firstly, assuming the outer diameter is the same, as well as the material and heat treatment being identical, it is certain that a solid shaft has higher bending and torsional strength than a hollow shaft. Secondly, assuming the cross-sectional area is the same, as well as the material and heat treatment being identical, a hollow shaft possesses higher bending and torsional strength. However, this is not unconditional; if the wall is too thin, despite its high moment of inertia and flexural section modulus, compressive stresses may cause local instability and failure in the compressed zone when subjected to bending moments. The heat treatment conditions mentioned above have no effect on stiffness, but they do affect strength. If the diameter is the same, then for bending resistance, torsional resistance, and tensile strength, solid materials are stronger than hollow ones. If the weights are the same, it’s not necessarily the case; it depends on the specific cross-sectional shape. A hollow shaft with a diameter of 100 mm, if the wall thickness is properly controlled, can have a higher bending strength than a solid shaft with a diameter of 10 mm. Hollow shafts are widely used in engineering, and this is because when selecting materials, strength is not the only factor considered; rather, specific strength and specific stiffness are taken into account. To give an inappropriate example: a solid shaft has 20% higher strength than a hollow shaft, but it is 50% heavier; therefore, from an engineering perspective, it is more appropriate to choose the hollow shaft as long as its strength meets the required standards. The above is a comparison between hollow shafts and solid shafts. From the comparison of their various properties, it can be seen that hollow shafts are used more widely than solid shafts to some extent.