(3) Steel tired wheels are used on steam
d. High Flange. The maximum flange height for
locomotives, some electric locomotives, and to a very
steel wheels is 1 1/2 inches above the approximate center
limited extent on diesel locomotives and passenger cars.
4-6. Wheel Defects
e. Burnt Rim. If a portion of the flange or rim
breaks off with a coarse fracture and rough granular
a. General It is not practical to elaborate on all the
manufacture and must be removed from service.
details of the defects that may develop In car wheels. A
general description of the various defects is given below.
f. Shattered Rim. If a portion of the flange or rim
b. Thin Flange. The minimum flange thickness for
parts and shows on parting a smooth surface (fig 4-5), the
wheel must be removed from service.
steel wheels in service is 15/16 inch as determined by
g. Spread Rim. If the rim widens out for a short
c. Vertical Flange. A wheel is condemnable for
distance on the front face, an internal defect may be
present, and the wheel must be withdrawn from service.
vertical flange when the gage applied as shown in figure
4-2 contacts the throat side
of the flange
1 inch above the
usually accompanied by a flattening of the tread, and the
wheel may or may not have cracks on the tread. This
condition is usually associated with a shattered rim. It is
usually less than 12 inches long and should not be
confused with the uniform curling over of the outer edge
of the rim around the entire wheel. This latter is a
common service condition and is not a defect Figure 4-7
illustrates a subsurface defect uncovered while the wheel
was being turned to restore tread and flange contour.
Unless these voids or flaky and/or laminated conditions
can be readily turned out (within the safe wear or turning
marks on the wheel), this wheel must be scrapped.
Figure 4-1. Method of gaging thin flanges, wheel
h. Shelled Tread
(1) When pieces of metal break out of the
tread surface in several places more or less continuously
around the rim, the wheel has a shelled tread and must be
removed from service (fig 48).
When excessive shelling occurs in
service, remedial measures should be taken.
Contributing factors include poor track, excessive speed,
excessive load, or the use of wheels of insufficient
i. Built-Up Tread. A built-up tread is caused by
metal from the tread or brakeshoe being heated to a
plastic state and then dragged or built-up around the tread
j. Grooved Tread. Wheels which have
circumferential groove or grooves in the tread to a depth
of 1/8 inch or more must be removed from service (fig. 4-
Figure 4-2. Method of gaging vertical flanges, wheel