My choice would be a piece of 4140/42/45 which is Q&T to around 36-38 Rc. Many folks use the term Cold Roll(ed) to signify a type of metal, when in reality it is part of the manufacturing process. Usually it is found in the lower carbon content steels, like AISI 1018 or 1020. My opinion is they are not suitable for your part. Not that they just plain wouldn't work, just not the best choice.
To finish the OD at 2.375, I would buy 2.500. And being as my preference is 41XX....tubing is harder to find. I have some P80 that might work for you, and save you from drilling a solid. I'll look in the AM. I can't remember the ID.
I was figuring on the 2.5" outer diameter. That'll produce more than enough in the way of chips. I first looked at the tubing with 1.5" inner diameter for the same reason but as you say, the choices are pretty limited for "tube". If you do happen across something (you lost me with "P80", I was good at 4140, 36-38 Rc., 1018 and 1020 but that was my limit) please let me know but don't go out of your way for it. I'm in no hurry. I've many other projects that need to be worked on as well.
4140 would make a great screw but it is much more expensive than this calls for. cold rolled does refer to the finial rolling process and true it can be any of several alloys. In all most every case it machines very well. I think 1020 would do just fine it is replacing a piece of cast iron. I stock several sizes of thick wall tubing I buy in 20 ft lengths. My supplier calls it stress proof. Machines very well not too expensive and it's pretty tough. This is a low stress app. low speed, low load, and for the most part limited use, Hand powered. If I wanted a shaper to use I would repin it and go on. If I wanted to restore it as close to original as possible I would have a blank cast and machine. This was boken but some serious abuse. You will never treat your shaper that way. Lock the gibbs before you start the ram unlock before you raise or lower the table and you won't have a problem.
As I'm mostly bereft of metallurgical knowledge I had to ask about alloys. Even though I understood what "cold rolled" means I still didn't know what metals were generally used in that process. That was even part of my consternation with the online metal places listing something as DOM "steel". I know what DOM is but a novice like me has no idea what group of alloys, if any, are generally used. When talking to me about metals you need to pretend your talking to a complete idiot (or at least
say you're pretending
). While I've got you here (I'll try not to get drool on anyone) would you mind if I "pick your brain" a bit? I've seen the term "stress proof" from time to time when I'm looking at metal suppliers but what does that really mean? Another thing you mentioned has me wondering as well, "low stress app. low speed, low load". The "low speed" part is pretty obvious but how does one define "low stress". "Low load" is also a bit of a puzzle. How low is "low" and conversely what would be "regular" and "high"?
As far as the shaper table goes, the table is a little over 300 lbs, the vise that sits on it another 200 lbs or so, the horizontal slide I'm going to guess another 500 lbs so before I even put a work piece on it the screw is supporting a half a ton. I could easily see myself putting another 300 lbs or so in a work piece. Now we add the constant pounding and vibrations from the shaper/cutting and the constant raising and lowering of the table. I would think a guy needs to have a steel that is hard enough to resist wear but not so hard as to become brittle. What ultimately fits that description, I have to bow to you guys that work with the stuff all the time.
Now, anyone know if they ever published a book, "Metallurgy for Dummies"? :biggrin:
Thank again guys,
-Ron
