CHROME-VANADIUM STEELS

I have used EN24T with success for highly-stressed parts. Not sure what its composition is, but it has a UTS many times that of mild steel, but still turns fairly easily. It is readily available from various of our usual retail sources; if they don't have it in stock they will certainly get it for you. I can't remember offhand where I got mine from, but it would have been Mallard Metals or Noggin End Metals.

David

Chrome Vanadium doesn't really tell us (or you) what the steel is - just 2 of the alloying elements it contains. I have seen those words on a lot of spanners over the years - though I have no idea why spanner manufacturers should go to the expense of adding the letters to the forging dies.

Assuming there are no particular chemical issues relating to the environment of use, select on strength of the steel for the required duty (on BS steels the 'condition' letter tells you the strength). Don't worry too much about composition of the steel.

Where there will be sliding or rubbing against another steel component, ensure a strength (hardness) difference between parts to reduce scuffing/galling.

For safety critical items (pressure vessels, lifting equipment - possibly couplings) the toughness of the steel is also important in avoiding fatigue failures. Toughness generally reduces as strength increases, so stronger is not always better - a balance is required.

BTW EN24 is a Nickel Chrome Molybdenum steel having about 0.4% Carbon (also contains Silicon and Manganese) .

For those components I'd be amazed if bog standard mild steel wasn't strong enough. It worked on my 5"g locos, and hundreds of others. If you want something a bit stronger then EN8, but I can't see that it's necessary

My guess is all those parts could be from one piece of gauge plate. Easy to harden & temper.

Neil