4140 Alternatives

[DaRaj]

We are making a special design wrecking bar using 4140 hex (7/8"). It is a two piece bar (head and shaft) that is welded after forming. We hot forge the shapes. We do not heat treat the welded assembly, because it appears to be sufficiently strong as it. (No one has bent or broken one in twenty years, except by using a "cheater" pipe extension.

The shaft length on these bars range from 24"-48". The head has forged "nail puller" slots on each end.

Is there any other material that you can suggest to use for these bars besides 4140, that won't have to be heat treated for strength? I can't imagine the mess of trying to HT a 48" long forged bar.

Or is there a HT process you can suggest to use if we change to another material of lesser strength?

 

[swall]

Why do you wish to change from 4140 and your current processing? From what you have told us, the product seems to be fine as-is.

 

[DaRaj]

The main problem is the lack of available sources for the material. As best I can determine, there is only one mill that makes 4140 hex in these sizes, and they have ENORMOUS tonnage minimums. The cost for this material is significantly higher that other hexes. I'm trying to find a lower cost solution.

 

[stanweld]

I suggest that you determine the tensile properties of your incoming 4140 bar; then you can make more informed choices. Materials like AISI 5140 (1% Cr), AISI 8640 (more expensive due to Ni and Mo additions)could be substituted. Depending on the current tensile properties, you may be able to use AISI 1045. In the USA, it is easy to purchase 4140 in small quantities from "stockists" rather than mills.

 

[swall]

What optional hex bar materials are currently available to you?

 

[rorschach]

EM Jorgensen shows to stock that size 4140/4142 CF annealed so does Ryerson Tull. Most of these major distributors will stock mill orders for you if you contractually agree to buy a certain amount. I'm not seeing the problem here. Are your quantities such that buying from distribution is not feasible? If that is the case, why is buying a mill run a problem? If your Quantites are that high, surely there is some way to deal with this.