A heat transferring device for a workpiece such as a pen barrel includes a pneumatic mechanism, a roller mechanism, a heating mechanism, and a rolling mechanism. The pneumatic mechanism is connected with the roller mechanism. The rolling mechanism rotates the pen barrel, and the roller mechanism includes an elastic force applying mechanism that applies an elastic force on the pen barrel during rotation. As the rolling mechanism rotates the pen barrel, the elastic force applying mechanism applies an elastic force to the pen barrel that keeps a roller wheel in contact with respective faces of the pen barrel during rotation. Thus, the force that the elastic force applying mechanism applies to the pen barrel is uniform and the respective faces of the pen barrel receive a uniform force. Therefore, the device can heat transfer designs on pen barrels having non-circular as well as circular shapes.