Steel Specification "ETB 150"?

[Carburize]

I have an old drawing for a fastener which refers to the material as "ETB 150 BAR" - I can't find any specification with this reference - anybody any clues on what it might be?

 

[unclesyd]

Could this be E.T.D 150?

http://www.niag.com/us/products/specialty/etd150.htm

 

[Carburize]

Could be!