I make my drills of very small wire, filing them at point and then tap the point (holding the wire in a very fine pin vise), thus flattening as well as spreading it, and then shape the cutting edges as spoken of above. When you have drilled sufficiently to hold a plug firmly, then have a piece of steel of spring temper filed so as to fit closely and so straight that it will not act too wedging (and split the arbor), drive it in, cut it off and turn down, finishing with an oilstone slip, and polish by running the lathe rapidly and with a piece of thin boxwood (or hard pegwood) charged with diamantine, being sure that the end of the pivot has no burr, thrown either way, over end or on side, for such a burr will cause a lack of freedom of a balance pivot particularly. This matter of setting pivots requires a longer experience than almost any other work, and it needs a long practice to do a nice job. If your split chuck will not hold your staff or arbor true, then use cement; but in this, too, you must be sure that your center is true, and that the sound pivot enters it perfectly. Sometimes you meet with steel so hard that you cannot touch it with a drill, in which case draw the temper of the staff or arbor you are drilling, and if it projects so little that you cannot draw the temper without injury to the wheel, then unstake or separate the wheel, and by drilling a hole into a piece of brass wire, about the size of the staff you are drilling, insert the staff in this hole, and then heat the wire near the staff and thus gradually and yet effectively draw the temper.
I consider it well for young workmen to practice pivot setting in some old and useless watch any spare time they may have, and thus become adepts at this work. Unhindered, I am not over on an average of one-half hour in setting any ordinary pivot, especially if I do not have to cement my work. If this is a balance pivot, be very careful to see that your balance is true and poised before putting on hairspring and roller. There are some pivots that are underturned (to make look tidy and light), and sometimes it is about an impossibility to put in a new one, and in this case, if an American watch, I always put in an entire new staff, and hence keep a full assortment on hand.