material

[dezerts10]

I was looking at mcmaster carr today and am thinkign of order some bar stock form them but i am confused now.

I need some barstock to make a piece for a spindle that i am going to press the stock snout into and then weld it in. but i will need to also weld plate to this piece so i can build the upright portion of the spindle. so heres my question. the mcmaster caar site says 4140 is chromolly and they also offer 4130. i probably will not be getting my material through mcmaster carr but which material should i buy? i have posted before onthe same subject and people say no to welding on 4140.

Gregg

[dezerts10]

heres the link tot he page i am asking about scroll down to the 4130 and 4140 section,.

http://www.mcmaster.com/param/asp/PSearch2.asp?reqTyp=parametric&act=psearch&FAM=steel&session=desc=Metals;steel&sesnextrep=510674651741959&ScreenWidth=1024&McMMainWidth=804

dont know how tomake clicky

Gregg

[dezerts10]

nevermind its made clicky for ya now

[Gordon]

You can weld 4140 just fine. it is just a higher carbon content. a lot of times thicker parts are made from 4140 instead because it is dificult to harden a thick section of 4130.

When welding 4140 the preheat postheat and all those precautions are slightly more important than with 4130, but people still get away without doing it.

[scottm]

They are both cro-moly, 4140 is .40 % carbon and 4130 is .30% carbon. 4140 is a potentially stronger material, but making the most of it requires more effort all around. 4140 is more critical about pre-heating and post-weld heat treating. A spindle is actually a good application for 4140 because the finished part is small enough to be normalized cheaply. But the 4140 downsides are more expensive, harder to machine, and more sensitive to weld. Its probably not worth using unless you can get help from a heat treater or a mil-spec certified welder.

[dezerts10]

so buy 4130 and weld it or...? i have an oven at work and a metalurgist who will help me along the way if i need it. I would like to not have to go that route though. so ill buy 4130 stock and have at it correct.

Gregg

[scottm]

Yeah, 4130 is pretty freindly. Just pre-heat it to 350-400° F before welding. Are you building an s-10?

[dezerts10]

attempting to. a firned and i have too much money tied up in ours to start something else.

Gregg