Fig. 2298.
Fig. 2299.
The next flat to file will be e, [Fig. 2299]. Now, in a small nut, the chamfer of the nut edge will be sufficient guide to the eye in filing e to an equal thickness (that is, equal for distance from the bore to a).
In order that the finished nut shall be so true that the nut gauge shall show that the flats or angles are true one with the other all around the nut, it is necessary that the flat e shall stand parallel to a; hence it should be made so by measurement with calipers, irrespective of its angle to either d or f. After e is filed it will serve as a base from which d and f may be filed to angle, while a will serve as a base from which the flats d and c may be filed to angle; but, while testing the angle with the gauge, c and d should be tried for parallelism, and f and b for parallelism, while the diameters across these flats should be equal on all sides.
Fig. 2300.