(a) Condemning defects. Driving, trailing, and engine truck axles with any of the following defects shall be removed from service immediately and repaired (see appendix A of this part for inspection requirements):

(1) Bent axle;

(2) Cut journals that cannot be made to run cool without turning;

(3) Transverse seams in iron or steel axles;

(4) Seams in axles causing journals to run hot;

(5) Axles that are unsafe on account of usage, accident or derailment;

(6) Any axle worn 1⁄2 inch or more in diameter below the original/new journal diameter, except as provided in paragraph (a)(7) of this section;

(7) Any driving axles other than main driving axles with an original or new diameter greater than 6 inches that are worn 3⁄4 inch or more in diameter below the original/new diameter.

(b) Journal diameter stamped. For steam locomotives with plain bearings, the original/new journal diameter shall be stamped on one end of the axle no later than January 18, 2005.