Tank wheels -- cast iron or steel?

I'm doing some research for a story I might write, and I was wondering -- were the drivers and idlers used on WWII-era American tanks made of cast iron (like rail car wheels), or steel?

DaveBj

 

Dave, I am just guessing but it's an educated guess: cast steel for the idlers, maybe cast iron for the drivers.

Cast iron, because of its high carbon content, is relatively hard and brittle and it has a low modulus of elasticity compared to steel, so it would not be ideal for idlers. Of the different types of cast iron, malleable iron might be acceptable for idlers, but it's expensive, so I'm going with steel for for that application. Gray iron is good for gears in high wear applications because of its self-lubricating properties (which is why it's used for disc brake rotors) and should work well for drivers.

Now that I've stuck my neck out, I'm interested in seeing if I'm in the ballpark....

 

Speaking for the M4 Sherman, trials were run on flame-cut steel sprockets vs. cast sprockets vs. forged sprockets to see which was the longest-wearing. (Flame-cut steel won, as the flame cutting also provided a face-hardened surface.)
M4 bogies and return idlers would most likely be cast, with the bogies having a rubber tire.
John

 

Cast iron like rail car wheels

Err, the wheels of rail cars are made of steel. Always were I imagine. A cast iron wheel would not have lasted a mile given the forces a bogie needs to handle.

 

I'm reading through WWII-era Life magazines; one article had a pic of a load of wheels and axles, and the caption said they were cast iron.

 

??? *search, search* In the 19th century wheels were made of cast iron but had a forged steel 'tire'. Later the cast iorn was replaced by cast steel and eventually forged steel.

 

Wouldn't be the first time Life got something wrong.