Anyone heard of DD17 nickel chromium molybdenum steel?

[AAA]

Got an old drawing (1950's) and wanting to find out a modern equivalent for this steel.

[Harold_V]

It sounds a great deal like 4340, but without knowing the chemistry, that may not be true.

The DD designation makes me wonder if, maybe, this is a Department of Defense spec?

How you been, AAA! It's been a long time.

Harold

[AAA]

It sounds a great deal like 4340, but without knowing the chemistry, that may not be true.

The DD designation makes me wonder if, maybe, this is a Department of Defense spec?

How you been, AAA! It's been a long time.

Harold

G'day mate. Long time indeed! Unfortunately, haven't had much time for forums lately, I've been busier than a one armed paper boy!
Yes, this is an Australian Defence Department drawing. Going through the metal charts I, 4140, 4340, EN25 is what I was looking at too.
Never even crossed my mind that DD might be Defence (that's how they spell it there) Department, so I'll follow up on that.

[warmstrong1955]

I took a look in some metallurgy books I have.....nothin' on DD17

I think you can cross 4140 off your list though.....no nickel in it.

43xx or 86xx I think cover most of the various chrome-moly-nickel alloys, but I'm more familiar with the run of the mill chrome molys w/o nickel.....like 4130, 4140 etc.

Bill