flat bar stock

[greenail]

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.

 

[mikey]

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.

 

[mmcmdl]

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 ?

 

[Bob Korves]

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.

 

[greenail]

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?

 

[chips&more]

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

 

[greenail]

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.

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.

 

[pacifica]

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 .

 

[mikey]

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.

 

[RJSakowski]

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.