Steel Grades

[DrFuManchu]

I am a new member and an old fossil so bear with me.I have been in engineering for over 40 years.I am a Senior Mechanical and Strutural Designer.I have worked on many of the largest Materials Handling Projects in the world as a Chief Draftsman and Senior Checker.

I recently started another Project as a Contracter.I was approached last week by this firm regarding a completed Project that twiked my curiousity.

Apparently they had what I concider a catastrophic failure to a 3 inch Diameter shaft.I asked what they had Specified for Steel.The reply was Grade 1040,but the Fabricator substituted 44W.My initial reaction was that Grade 1040 is an Alloy Steel usually used for its Tensile properties.Grade 44W is generally used for Structural applications.

Was I correct in this assessment?

Warmest Regards,

 

[mrMikee]

Per the Ryerson catalog.

1040 is a medium carbon steel. I think this is a spec commonly used for shafting, at least where I have worked. I've also seen it used for gears.

I don't know what 44W is but I did notice that Ryerson had a Rytense 44 (in an old catalog) that was 1144. It has a slightly higher carbon content but still called a medium carbon, and is an alloy. Mechanical properties are slightly better.

I hope someone has better information than this however. The situation you describe requires that you have precise information.

Regards,
-Mike

 

[JStephen]

Grade 1040 is a medium carbon steel (not an alloy steel). The "10" is plain carbon steels; the "40" is 0.40% carbon. As I recall from long ago, that's getting to the point where you can begin to heat treat it. You'd need to know whether it was intended to be heat treated, or cold rolled, or what, to compare to the other steel. I would assume the Grade 44 was a 44 KSI yield material, typically hot-rolled.

 

[PSlem]

44W is a Canadian code. It is 44,000 yield. But like A36 the as delivered strength is probably way beyond. I am curious the nature of the shaft failure. I have failed them when there was a tangential score. Also is this the first time this design was used? Was shaft whipping a possibilty?

The optimist sees the glass as half full. The pessimist sees the glass as half empty. The engineer see the glass as too big.