Steel equivalencies

[woodyrod]

Hello all,

I am about to embark on a new manufacturing endeavour, and would like the help and advice of knowlegeable members:

I will be building rifle actions. I have all of the materials specified by the designer/metalurgist. The main body is plain 4140 in pre-hardened state, post ionic nitrided and finished with some other treatment for asthetics (likely cold bath bluing). The bolt body, is however, being a pain to find material for.

The material is 36nicrmo16 (1.6773), and obviously, there is no AISI/BS etc equivalent, although AISI 4340 seems to have some relevance. The bolt body is to be heat treated to 52 HRC. It has internal holes bored on center for firing pin mechanism etc, and is probably on average two thirds its radius in thickness. Overall length about 5 1/2 inches, diameter about 1 inch

What other steels have a similar makeup, or similar end properties that people here may know of? What suppliers have this material? Are there any people here in Australia that know of suppliers? I have had a number of conversations with Bohler Udd. with no success so far (except 4340 that they don't have in stock anyway).

Regards

woodyrod

 

[ScottishMet]

Take a look at BS 970 817M40 (En 24), it "might" make the properties you need.

 

[Maui]

I'd recommend speaking with Greg Olson at Bohler-Uddeholm located at 440 Quadrangle Drive, Suite D in Bolingbrook, IL 60440. He should be able to put you in contact with someone who can help you. I would offer you his email address, but it is against site policy to publish email addresses in these forums.

Maui

 

[NickE]

Ask your metallurgist for a different material, to usa specs?

 

[woodyrod]

Thanks for replies.

I have asked for other equivalencies, and in particular, US ones. I can ask for the actual ideal chemical composition from the metalurgist, and post it here, then it can be looked at from other points of view - other than just reference numbers.

I will repost when I have the other data.

woodyrod

 

[woodyrod]

Ok, different approach now. From my metalurgist:

Find a similar material, then we go from there.

Anyone suggest a good replacement for 36nicrmo16 (1.6773) for the stated purpose of using it in a rifle bolt, and at 52 HRC???

 

[Metalguy]

In that small diameter, properly heat treated 4140 will be fine.

Gold is for the mistress - silver for the maid
Copper for the craftsman cunning in his trade.
"Good!" said the Baron, sitting in his hall
But iron - cold iron is the master of them all.
Rudyard Kipling

 

[TVP]

Latrobe Steel in PA produces LESCALLOY® 35NCD16 VAC-ARC® which is based on a French grade that is equivalent to 36NiCrMo16. You can find additional information by using the following link:

http://www.latrobesteel.com/assets/documents/Sheets/High_Strength/35NCD16.pdf

Beyond this, you would need to really determine what type of properties you need, and what alloys may have sufficient hardenability, toughness, etc. Possibilities may include 4340, 300M, maraging steels, and some proprietary grades from producers like Latrobe, Cartech, and Allvac.

 

[woodyrod]

Thanks. I will now follow up with this further information.

 

[Robertmet]

Unless you're using pressures far above typical rifle cartridges there is no reason why 4340 would not be suitable. All the old Mauser rifles were made of just low carbon steel ,case hardened and these old guns are used for modern cartridges.Today most rifles are made from 4140 and the stainless steel rifles from 416.They work fine even on the highest pressure cartridges [65,000 psi].

 

[steelsteve]

Not specifically related to this grade, as I only found one equivalent, which was a French grade on the Arcelor Mittal site.

A helpful starting point, generally might be in one of the steel search engines that I have been developing, one powered by Eurekster, and the other by google.

They are by no means perfect, but much better than more general searches.

They can both be accessed form my blog (top left hand sidebar).

http://www.steelstrip.co.uk/steel-strip/