Cylinder end covers

Hi, On the 2 in scale Traction Engine i'm building the cylinder is made of cast iron. The drawings say the the end covers can be made of cast iron or gunmetal, but is it alright to use steel instead. Or are the expansion rates of cast iron and steel so different that it;s not a good idea to use steel. Can someone enlighten me on this please.

Garry

Expansion coefficient tables are available on the net.

Think here, perhaps, of corrosion at steel at elevated temperatures and over long periods.

Mine are cast iron since I bought castings, and it's prototypical. The front cover is just a flat plate, so if I hadn't bought a casting I would have used some hot rolled plate as it distorts less than cold drawn, and seems less prone to corrosion. For the rear cover anything other than a casting would have been a right pain:

The expansion rates of low carbon steel and cast iron are pretty similar.

Andrew

Like Andrew suggests, I have used hot rolled plate for cylinder covers on a large 71/4" narrow gauge loco.. NDIY's concerns have been totally groundless in this particular case.

Andrew.

NDIY's concerns have been totally groundless in this particular case.

It was no ‘concern’ to me, at all. It was just a suggestion, as I could see no other reason for not doing it. Andrew’s suggestion of distortion with some (or thin section) steels seems pertinent.

Thanks everyone for your replies. I will now make the end covers out of cast iron as suggested.
Garry