Information needed on 308 MOT stick rod

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Hi,30 years ago I bought a couple ton of rod from the US military. In it was some 308 - MOT series stick electrode. I've used it and would like to replace with similar but cannot find a supplier for the 308 with an MOT specification - nor can I find what the MOT specification means. Does anyone know a supplier or have an answer on the specification?Thanks,Ron
Reply:Look a bit closer Ron and see if it isn't marked 308MoL, (electrode designed for welding ASTM CF3M stainless castings).308MoT would be a designation for a bare TIG rod of similar purpose.Matt
Reply:Do a search online for 309 MOL rod. It is a stainless rod that is heat, crack, and corrosion resistant.Buy a small sample to try. I think you may find it welds the same.ScottFab ManagerWelders360.comNew guy.
Reply:Hi Folks,What I have is very clearly 308 MOT. They even have it nicely printed on the rods. It was made by Alloy Rods whom was aquired by Esab.Thanks,Ron
Reply:Oh, Matt,Thanks for the reply. What I had was 1/8"x16" stick electrode. Nearly a white coating with black printing for the alloy spec.Thanks,Ron
Reply:Originally Posted by Ron OhlerOh, Matt,Thanks for the reply. What I had was 1/8"x16" stick electrode. Nearly a white coating with black printing for the alloy spec.Thanks,Ron
Reply:I couldn't find the blue stainless guide Ron, but did find it in the 1978 guide. Pics are below.You could ask your weld supplier armed with the chemistry, but I'm betting it will be a no go. I suspect they will point you to MIL 308 Mo which appears to have a safer chemistry all around.Current Esab page for MIL 308 Mo here; http://www.esabna.com/EUWeb/AWTC/Lesson5_28.htmMatt Attached Images
Reply:Hi Matt,WOW! You did find it. I'd contacted another welding supplier today. Airgas. They contacted Crown Alloys who said there was no such thing. I did make a mistake when I said they were 16" long rods. They were 14". What I was remembering was the full spec was 308 MOT-16. You showed this in your copies. I recalled being told it was used for welding armor plate. I used it for various cast steel and general hot rolled applications including gravel equipment joining of cutting edges and ripper teeth and repair of cast steel or some applications needing a tough weld suitable for dissimilar metals. Yes,I did do some stainless plumbing items also - assumed to be 308. I never had a failure with it in any application. Darn nice running rod - just heats up significantly like any stainless stick likes to. I don't know metalurgy well enough to know what issues you mention a concern with. Can you elaborate?Thanks so much,Best regards,Ron
Reply:Hi Ron, I don't like all the carbon in this rod for SS. It makes sense for manganese steel or joining manganese to carbon steel and welding of ASTM CF3M or ASTM CF8M castings.With the .15 carbon when welding an 18-8 (301,302,4,8 etc.) there is going to be some chrome carbide forming with the chance of the parent 18-8 going "lean" and losing chrome. Of lesser concern but should be noted is there will be some ferrite in the weld.It's safer and cheaper to use a recommended filler with 18-8. I bet it also would be cheaper to use 309 to weld dissimilar steels than to use MIL 308 Mo (.11 carbon) with strength only going down from 98ksi to 91ksi.MattMatt
Reply:Hello Matt,Thank you so much for your help and efforts. I've tried to find this data since last year. Hard to believe that 3 different companies couldn't tell me what I had.Thank you,Ron Ohler