SOLIDWORKS Design & Help

There are lots of bend tables available, but some really general rules of thumb are:  Bend radius should be equal to or greater than your material thickness (so .125 in this case).  A K factor of .45 should be a good start (https://www.thefabricator.com/article/bending/k-factors-y-factors-and-press-brake-bending-precision will give you more detailed info)

The biggest thing with SolidWorks sheet metal, is what exactly are you bending?  If you want a 90 box (ie… flat w/ 4 sides bent up 90 at a certain desired height), you should use edge flanges.  Create your rectangle base-flange, then pick your edges and drag up. 

Short of knowing exactly what you're planning, I'm going to be guessing and there are a LOT of ways to draw.  If you have a picture or hand sketch, I could be more specific.  The nice thing with flanges, your flat pattern will include the extra material required for bend deformation.

More or less I am making a box (custom electrical enclosure). I always create my sheet metal pieces such as the way you have described so glad we are on the same page there. I have a sheet metal bending table for most gages of sheet metal, but not many for SS which is why i was asking this forum. I am assuming the bend radii and k factor would be different for a SS since it is harder than regular sheet metal. For instance right now in solidworks for say 11 GA sheet metal I use a bend radii of 0.005 and a k factor of 0.275 and that seems to work pretty well when I put the flat views on my prints. and by that I mean the cut out prior to bending comes out to the right size. So i am looking for the parameters for 304 SS that will have the same outcome. I will look more into the table and information you have given me. I appreciate the help!

So we bend a lot of mild steel.  Our bend radius rule of thumb is the minimum radius = material thickness.  We bend lots of stainless, which in terms of hardness, is very similar to mild steel (a36/gr50/cq)  If I were to start folding, I would use .125 and a K-factor of .45

Joe;

As a designer, I was taught

1.  since different fabrication shops have different bending machinery with unique capabilities; always ask the fabricator which variables to use for their machines, and
2. send the fabricator the 3D bent part, and let them determine the flat pattern themselves, based on how they will make the part. (this also moves the liability from the designer to the fabricator)

do you agree with these?

@jack

This is the most common way as each bending machine has its own unique bending factors but if you are doing it for your own company then the operator should bend some material and the give you the Details

Jack,

I was out yesterday, but YES!  I completely agree.  We have one customer, for which they actually bend a lot of the parts we are now doing for them.  Their tooling is MUCH different from ours, so we frequently have to tweak the flat patterns. 

To summarize, I would use what has worked best in the past, which unfortunately is only known through trial and error.  Otherwise, start with the K-factor table.  If you can afford to, cut extra parts.  Due to our lead times through our own shop, we have say a 50 piece order, we would do 3-5 sample pieces, hoping we could get the bend program correct before cutting all 50 pieces for the run.

in me bending machine K faktor its 0.61 in solidworks added this date and any OK (Durma 3175)

Most good shops will have tested/recorded data for their tooling and the material, ask them. Tooling is different in each shop and it affects the results. It's a good practice to develop a relationship with the shop, they can help/hinder your design requests. Shifting liability to another department doesn't help produce results as well as communication and co-operation.

If you send a step and a drawing the "shop" it will use its own cutting sizes and bend tables to reproduce your part so long that they can be bent on a press brake machine that they own. The drawing is the most import part as this should be dimensioned with tolerances you require. You should not need to know the k factor for your part. This is up to the "shop" to determine based on the material and their own "unique" bending table.

CadCloud is correct.

Please dont just let your buyer send the "shop" a pdf of your drawing, the .step file is a valuable addition. Having to redraw parts you know are already drawn at the customer is obnoxious.

hi my machine bending in radius 3 mm k faktor is 0,45 is it correct or not

steel 304 1 mm thick

I always do the same thing.

Typically, you need the K-factor to match your own capabilities.  Our shop (since my original post) did a white paper on our bend parameters.  .33 is what we typically use to represent our capabilities.

This is a good resource I use a lot:

https://www.lehisheetmetal.com/engineering.htm

There are formulas out there as well.

Also depending on the manufacturers bend dies, etc the results may not be exactly the same as the resource above.

ı made 0,35 done for 1 mm stail steel