# flat bar stock



## greenail (Dec 12, 2018)

wondering the best way to make long flat barstock without a surface grinder? 

Here is a video of my setup trying to skim 8mm bar stock.


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## mikey (Dec 12, 2018)

I usually just by precision ground stock as needed. You can buy it in low carbon steel or tool steel. Much easier than trying to mill it precisely flat.


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## mmcmdl (Dec 12, 2018)

When you cut thru that scale , your part will stress relieve itself , introducing twist ( especially stainless ) . Larger pieces as that could be done on a Blanchard grinder relatively cheap if you had access to one near your area . I'm taking it the thickness was critical and not available ?


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## Bob Korves (Dec 12, 2018)

Yes, metals commonly warp when one face is machined.  That interferes with it being flat and parallel when completed.  Sometimes, especially with cold worked metals on only one wide side, it will warp a lot.  Whether you use a mill or a surface grinder will not change the outcome, only the surface finish., and maybe the extent of the warpage, depending on differential temperatures when machining it.  About the only way to avoid it is to use stress relieved metal stock, and then not induce more stresses while working it.  That is my understanding, without a lot of experience.


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## greenail (Dec 12, 2018)

mikey said:


> I usually just by precision ground stock as needed. You can buy it in low carbon steel or tool steel. Much easier than trying to mill it precisely flat.


 
where do you buy your stock?


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## chips&more (Dec 12, 2018)

What kind of tolerance are you trying to achieve? Is surface finish going to be critical? What is the material? Put the part down onto the table and use edge and toe clamps for probably your best results…Dave


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## greenail (Dec 12, 2018)

chips&more said:


> What kind of tolerance are you trying to achieve?


I'm trying to do the best I can with a mill.  I don't have a surface grinder.



chips&more said:


> Is surface finish going to be critical? What is the material? Put the part down onto the table and use edge and toe clamps for probably your best results…Dave




but wouldn't using only toe clamps only cause it to flex, and since it is a spring, it would flex back when unclamped?  Shouldn't it be shimmed if put on the table?  My thinking was to limit the reference points to hold it in it's natural unstressed shape.

buying ground stock would be worth the savings in time.  Is there a thickness/length ratio where this stops being economical?  I suppose at some thinness that parallel is much more important than flat.


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## pacifica (Dec 12, 2018)

I might  mill it myself if I already had the steel at an inexpensive price.  The more precise you want the steel the more it costs. precision ground can be 2x or 3x the price of cold rolled steel. Hot rolled is usually least expensive .


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## mikey (Dec 12, 2018)

greenail said:


> where do you buy your stock?



You can buy it at any industrial supply house (MSC, Travers, etc), McMaster, Amazon, Ebay. Determine what you need and buy it as closely dimensioned as you can get it.


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## RJSakowski (Dec 12, 2018)

The question is what is the intended use.  That will determine the machining method.  Are you looking to achieve a flat surface or a uniform thickness or both?  Even precision ground flat stock is usually not rated for flatness.


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## NortonDommi (Dec 13, 2018)

I'm with *mikey* lot less hassle just to buy what is needed but if I had to mill some bar stock like that I would clamp direct to the table with at most some thin paper underneath.  Clamp along one side/edge of bar and mill the other then swap.  Once one side was done flip over and repeat. The aim being to secure the part with even support and no flex.


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## BGHansen (Dec 13, 2018)

Only thing I might have done differently is to pull the vises and clamp the piece directly to your table.  How'd you determine the height of your jack in the middle?  I'd probably height gauge the stock at one of the vises and adjusted the jack after the two vise jaws were tightened so the stock at the jack was at the same height. 

Looks good, as mentioned above, depends on the tolerances you are after.

Bruce


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## mcdanlj (Dec 13, 2018)

Recently, I clamped directly to the table in order to put a long D profile in a 8mm rod. I shifted clamps in short sections to avoid chatter, so I milled about 2" at a time. It was a stable setup, just required enough clamps to keep it stable while shifting clamps near the cut.


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## middle.road (Dec 13, 2018)

But when the budget is tight - how much more does flat ground stock cost? Quite a bit more, at least a factor of three. . .
It would be nice to always go 'top-shelf' however it is not always doable. 
It would also be nice to buy what is needed, and then we'd all have new factory fresh machines with a warranty and not have to mess around with repairs and the like. 
I'm facing this same situ currently without any tolerances, just need to clean it up to around .160-.180"


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## mikey (Dec 14, 2018)

middle.road said:


> But when the budget is tight - how much more does flat ground stock cost? Quite a bit more, at least a factor of three. . .



Almost all the flat ground stock I have is from ebay and at a fraction of its retail price. I am almost always using it to make a precision tool with and it needs to be precision ground so I have very flat surfaces that often has to lock two pieces with a single screw. All the stock I've gotten has been quite flat, although size has been nominal. Works for me, at a cost that is easy on the pocket. Beats the hell out of trying to mill it flat.


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## mmcmdl (Dec 14, 2018)

The customer will pay either for the ground stock or he will pay my TIME to mill it . Either way , he's going to pay . If it were my G job , I would buy the ground stock and be done !


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## NortonDommi (Dec 14, 2018)

My local situation is that the major steel suppliers are only to happy to get rid of any drops at a discounted price and a few have listed on their websites grade, alloy, dimensions and finish. I have had to wait 1 working day on occasion if coming from another city but it is worth a phone call or Email and there is that balance between cost and time.  Having chewed up tips etc on Mysterium sometimes I save up if I have to to be working with a known quality.


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## mcdanlj (Dec 14, 2018)

mikey said:


> Almost all the flat ground stock I have is from ebay and at a fraction of its retail price.



Do you have sellers you trust, or is this just that you've had generally good luck searching for random drops and buying them?


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## middle.road (Dec 14, 2018)

mikey said:


> Almost all the flat ground stock I have is from ebay and at a fraction of its retail price. I am almost always using it to make a precision tool with and it needs to be precision ground so I have very flat surfaces that often has to lock two pieces with a single screw. All the stock I've gotten has been quite flat, although size has been nominal. Works for me, at a cost that is easy on the pocket. Beats the hell out of trying to mill it flat.


Can you put up some links? 
With the exception of some acrylic and plastic - prices to me seem to be the same as retail.
The last material I bought in spring was some 1" dia. brass tube and rod, it was cheaper through a supplier on-line than eBay.



mmcmdl said:


> The customer will pay either for the ground stock or he will pay my TIME to mill it . Either way , he's going to pay . If it were my G job , I would buy the ground stock and be done !


Good to have disposable income for that, for some of us that is not always the case or perhaps frugality comes into it.


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## mikey (Dec 14, 2018)

mcdanlj said:


> ... just that you've had generally good luck searching for random drops and buying them?





middle.road said:


> Can you put up some links?



On occasion, I buy retail from Amazon; they often have stock for pretty good prices and Prime shipping. Most of the time, I buy what I need on ebay. Somehow, it almost always seems to turn up just about when I need it. My favorite seller is no longer on ebay for some reason or I would link you to him.


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## TakeDeadAim (Dec 30, 2018)

In checking with my local Speed Metals store 3/8"x2"x24" ground flat is about $80, the same size 1018 is about $40.  Not sure how long I would play around at the mill trying to get flat and smooth on both sides for $40.  I have found some bargain buys on aluminum, brass, copper and ground stock on ebay.  You have to watch and be ready to buy when you see it and keep it for when you do.  Example being a guy sold me two large flat rate boxes full of aluminum round stock 3/8 to 1" for $25 each.  I bought 2 pieces salvage copper buss bar 1/2" x 3" x 18" pieces for $35 a piece, shipped, a few marks on it and some tarnish but nothing I have not seen on new stock.  It made very nice jaws in both my Starrett bench vices and there was plenty left over for customer jobs that more than paid for my now "free" vice jaws.


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