In the case of round work the same rule holds good, inasmuch as that a round bar may be forged smaller to some extent, either by hammer blows or by Swaging, but if the forging by hammer blows be excessive, hammering hollow is liable to ensue.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose
2859. For very small work, on which the hand hammer is sufficiently heavy to perform the Swaging, a spring swage may be use: thus, in Fig.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose
The welding of the whole may then be done at one heat, Swaging the outside of the collar first.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose