Sheet metal bend cost
Sheet metal bend cost
(OP)
Hi all, I have a sheet metal question. I am going to have a sheet of 4mm thick carbon steel bent at 90 degrees. My current design calls out a bend radius of 20mm. The shop just got back to me and said it will be cheaper if they bend the flange at the standard bend radius. They said if they bend it at 20mm radius, then they would have to use a special die for this.
I am assuming a sheet metal shop would have the equipment to bend a 20mm radius flange. I don't understand how this would increase cost. Any insight? Thanks
I am assuming a sheet metal shop would have the equipment to bend a 20mm radius flange. I don't understand how this would increase cost. Any insight? Thanks





RE: Sheet metal bend cost
What they mean is "...at a radius that we already have a die for..."
Obviously if they don't have the necessary die the will need to either make or purchase one. And they will pass that cost on to you as a "tooling cost".
Ask around. You might find another shop that already has the necessary die on hand.
Or, ask the shop you are dealing with now what they can do. I wouldn't be surprised if they say they can do 3/4".
RE: Sheet metal bend cost
http://sheetmetal.me/air-bending/
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RE: Sheet metal bend cost
RE: Sheet metal bend cost
RE: Sheet metal bend cost
20mm may be a large radius for a sheet metal bending die. Ask them what they have.
My understanding is that they can bend any radius you want. If you get weird, they "bend in air". This is a more expensive and a less accurate process. It may require a significant level of operator skill.
--
JHG
RE: Sheet metal bend cost
Typical sheet metal bending is done with a radius roughly equal to the metal thickness. Hard metals closer to 1.5 times thickness. Much bigger, and it becomes difficult to control the form. Too small, the metal will crack.
There are standard tools in catalogs. However, I find many small shops have their own favorite tools on hand and are not too keen on building or buying more. Especially true if you are a small-time guy making small quantities.
If you can design in such a way that you can be flexible about actual bend radius, metal shops can find a way to help you save money using what is available.
Use what is abundant to make what is rare.
RE: Sheet metal bend cost
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: Sheet metal bend cost
RE: Sheet metal bend cost
"Art without engineering is dreaming; Engineering without art is calculating."
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RE: Sheet metal bend cost
RE: Sheet metal bend cost
Tunalover
RE: Sheet metal bend cost
If this has never happened to you it's only luck or your charming personality, of which I have neither.
Worse is needing a box die; they never have the right length so the bend gets sloppy somewhere along the way.
RE: Sheet metal bend cost
It helps me when I'm designing a part as I simply pick from their list of the shapes/holes/corners/obrounds,etc.. saves the back and forth time of "we don't have X can you use Y"
Back to the OP..
Get a few catalogs from the tooling makers like..
http://marketing.wilsontool.com/acton/attachment/8...
http://marketing.wilsontool.com/acton/attachment/8...
Most have just about everything "standard" in these catalogs. 20mm is very large for a 4mm sheet IMO and would be "custom" for one vendor while another would have it.
Like everyone else said.. simply ask the vendor "well then what do you have thats close to that without going custom?" and see if that works for your application.
Most press brake tooling in the US comes standard with a radius in inches of (.031/.062/.125/.187/.250)
RE: Sheet metal bend cost
You are fortunate to work somewhere that has such good suppliers that take the "trouble" to tell you what they have. That's a great arrangement indeed!
Tunalover
RE: Sheet metal bend cost
When air bending, springback is a significant factor in accuracy and repeatability.
If you want an accurate bend at that radius, you need consistent material and good equipment at the least.
For consistency bends are often done by 'coining', where the press drives the punch and material into the die to make sure most or all of the material has gone into yield.
The thicker the material, and the larger the radius, the more tonnage it takes to drive the material into yield. (depending on bend length, may require a bigger press)
And the tooling has to be heavy enough to withstand that usage.
fun, fun, fun.
Jay Maechtlen
http://www.laserpubs.com/techcomm