Fig. 794.
The mandrel thread may be caused to fill the nut thread better if it be provided with three or more splits a, b, c, [Fig. 794], a hole d being drilled up the centre of the mandrel, the thread may then be turned somewhat large, the splits permitting the thread to close from the nut thread pressure.
Fig. 795.
When a mandrel is fitted to the sockets for the lathe centre, it should have a thread and nut, as shown in [Fig. 795], so as to enable its extraction from the socket without striking it, as has been described with reference to [lathe centres].
Fig. 796.