1144 Stress-proof equivalent in Europe?

[DiegoVV]

Hi fellow members,

For the crankshaft of my next project (An Offy 270), the plans asks for 1144 to make the crankshaft. I understand that this steel combines great machineability with low internal stress that will help in keeping it straight when removing large amounts of material.

The problem is that I don´t seem to find the equivalence of 1144 in the European standards. Does any colleague from the old side of the world have any suggestion?

Thank you all!

 

[Bessemer20]

The European equivalent of 1144 stress proof steel is typically considered to be EN 10088: 44SMn28 under the European standard, which is a steel grade with similar properties to 1144 steel, particularly its high strength and good ductility.

 

[TonyM]

EN 10088 is stainless steels standards. https://bssa.org.uk/bssa_articles/c...BS EN 10088-3 is,duplex), grades are included.

 

[Bessemer20]

That was what come up in a quick Google search.

 

[TonyM]

The nearest chemical composition is probably EN16C That probably makes it easy to machine but "stressproof" relies more on the production method than composition.

 

[djc]

That was what come up in a quick Google search.

What comes up in a slower, more thorough Google search?

If the doctor told you you were to die tomorrow, you would probably seek a second opinion before going public with the news.

This is quite comprehensive (but does not contain 1144):

https://www.michael-smith-engineers...o/MATERIAL-GRADE-COMPARISON-TABLE-for-Web.pdf

This has 1140 and 1146 on it, also downloadable as a pdf:

https://www.hastingsmachine.com/steel-grade-equivalency-table-3/

 

[Bessemer20]

What comes up in a slower, more thorough Google search?

If the doctor told you you were to die tomorrow, you would probably seek a second opinion before going public with the news.

This is quite comprehensive (but does not contain 1144):

https://www.michael-smith-engineers...o/MATERIAL-GRADE-COMPARISON-TABLE-for-Web.pdf

This has 1140 and 1146 on it, also downloadable as a pdf:

https://www.hastingsmachine.com/steel-grade-equivalency-table-3/

And here comes the real reason I try not to help anyone on a public forum...

 

[Nerd1000]

Stress-proof seems to be a US special, I certainly wasn't able to get anything close in Australia.

You might consider alternative grades. The main requirements are sufficient hardness to run against the bearings and sufficient strength to avoid bending the crank. Below are 3 options which all meet the hardness required:

1045 or C45 will provide similar mechanical properties to 1144 but somewhat more difficult machining.

4140 or 42CrMo4 will be stronger and more challenging to machine.

Ductile iron (EN-GJS-450-10) will be easier to machine with minimal distortion in my experience. However its strength is only comparable to mild steel. This may well be sufficient, often in model engine parts 1144 is chosen more for its hardness and machinability than its tensile strength.