There are many considerations when buying wheels for your
industrial applications; not the least of these is the material
from which the wheels are made. As with any equipment, correct
selection depends on the specific use. Choices include cast
steel, cast iron, ductile iron and various alloys. Here we will
be looking at the pros and cons of steel v. iron.
A wheel that is harder than the track it runs on will cause wear
to the track. It follows that if your track is harder than the
wheels, the wheels will wear out
faster. Generally, if you must choose track or wheels of a
softer material, you will want to choose wheels that are softer,
because wheels are less expensive to replace. Cast iron is
harder than steel, so this is one factor in favor of steel
TRACK TWISTS AND TURNS
One of the biggest advantages of cast iron is that it is
extremely long-wearing. Even when its exterior rusts after
periods of exposure, its structural integrity can remain intact.
But be aware that iron’s life may be cut short when you have
applications that add a lot of stress such as tracks with
twists, turns and level variances. Steel is more elastic than
cast iron and is more forgiving of irregularities. Flanges on
cast iron wheels are more easily broken by irregular tracks than
steel, and broken wheels can create not only downtime, but
If you have an irregular track, the elasticity of steel wheels
means you will likely need to replace them less than you would
iron wheels. For many applications, this is the deciding factor
between steel and cast iron.
EXPOSURE TO CORROSIVE CHEMICALS, GREASE AND OIL
Cast iron stands up better than steel under the harshness of
messy applications, all else being equal.
EXTREME HIGH OR LOW TEMPERATURES
If your equipment will be operating under extreme temperatures,
you may want to consult an engineer regarding materials. They
may recommend a custom steel alloy and heat treating.
HIGH IMPACT AND WEIGHT
Flanged cast steel wheel on white background
If you evenly disperse loads in your carts, cast iron offers
greater resistance to fatigue. If your loads vary and shift, you
may want to choose steel.
Some wheels are constantly subjected to jarring high impacts,
often during loading or unloading. Constant high impacts cause
fatigue in the metal over time. Although cast iron has better
fatigue resistance than steel, because steel is more elastic
than iron, it can adapt better to stresses. Usually you will
want to choose steel in high impact situations, because steel is
much less likely to shatter, creating a safety hazard.
An intermediate option to consider is ductile iron, which has
features somewhere between cast iron and steel; it has much more
impact and fatigue resistance than cast iron. Ductile iron
cracks less easily than iron under stresses, because the
graphite of the composition is in the form of nodules rather
than flakes. In cast iron, the sharpness of the flakes can
create stress points that result in cracks.
Whatever material you choose, make sure the wheels stands up to
manufacturer’s limits. Our Foundry uses a Safe Working Load
standard, but you must consider that your load may not be
subjected to ideal conditions and may require a heavier duty
wheel than the SWL indicates.
A wheel’s elasticity helps to keep the load stable, and we have
already seen that steel is more elastic than iron. If you have a
load that must be kept extremely stable such as a dry kiln
lumber cart where lumber is stacked optimally for drying, steel
may be the best choice.
Cast iron wheels are usually priced lower than steel wheels, but
if you need the elasticity steel offers because your track is
inconsistent or your loads vary, steel may last longer and thus
be more economical in the long run. Downtime can quickly eat up
any savings you realize by buying less expensive wheels.
An intermediate option to consider is ductile iron, which may be
less expensive than steel.
Usually aesthetics are unimportant in industrial applications,
but if your use is the exception, cast iron may be your best
choice. Cast iron is better than steel for intricate, detailed
designs, and may also be used for ornate reproductions.
When choosing the best wheels for your application, our foundry
can give you guidance. But if there is any doubt, you will want
to consult with an engineer. Ultimately, the best choice is the
metal wheel that will keep your production line running
efficiently and safely.
HOME PAGE | CASTING BLOG | CONTACT US