One of the supporters which are several times mentioned in this chapter is represented on the anvil and beneath the axle in Fig. 201. For long shafts several supporters are required during the forging, and two are required during the twisting of an axle, that the axle may be supported at both sides of the crank. Many supporters are flat-bottomed, and some have square stems; these are used when it is necessary to maintain a shaft in one precise situation, and the square stem is therefore put into some convenient hole. Some supporters have angular gaps instead of half-round ones, that the gaps may fit a number of shafts of various sizes.

For the advantage of having a hard, smooth surface for the gaps of supporters, to allow a rough shaft to be easily moved while in contact with the gap-sides, it is advisable to make supporting blocks of either Bessemer steel or hard cast iron.