Looking for a generalized gauge and sheet metal bend table for Aluminum. We are not a fab shop, but I make all my own sheet metal parts and send out the drawings for Fabrication.
Searched google for information, and though I can find the gauges I have not been lucky enough to find the bend radius and the k-factors. Does anyone have anything they could share?
Hi Scott, you can make your own bend tables. Radiuses will vary depending on the machinery you use to bend the part, because a 1/4'' aluminium plate can be bent with many radiuses.
As you know, you could use a 1/4'' aluminium plate and bend it as you wish with the radius you wish, this is why you can't find information on the internet about standard bend radiuses. I would suggest building it according to the machinery you use to do the bending, or else just go with your feeling and put the radiuses in relation with the thickness.
For the K-Factor, it all depends on what type of material you use but I'd say you can use 0.33 as a K Factor for aluminium, that is what we use here. I don't remember what process I went through to get the K Factor though.
You can look on the internet to find the thickness of each gauge size. I could probably give you a start-up template and you'd have to fill everything else according to your specifications, would that do?
Its a starting point...
At my previous employer we tried using whatever on a Radius and that turned into a really bad ordeal and a lot of rework. However, now I don't send out the Flat patterns. None-the-less, I would like to be some what close to what we expect to get in. We don't use the same fab shop each time, so the k-factors and radii is going to vary I am sure of it
Thanks Alex!
Hey Scott,
Long time no see!
My recommendation would be to get with some of the fab shops that you will be working with, and see what they have for tooling - do they have a preferred bend radius?
(They might even have K-Factor bending information that they could share with you.)
The more information they give you, the more time they save when your job hits.
How thick of material are you using? Do you have a bend radius preference? 3003 is soft and bends really nice . . .
todd
Depending on where SWW is next year you might see me there. I have no desire to go to LA ever.
I did contact one of our shops and what they gave me didn't help me create a bend table or any k-factors. I already have one for Carbon Steel, now I want to add Aluminum since we are doing a lot of work with that material recently. Right now we are just using 6061 plate ranging between .063"-.125" and the radius I have been using is always about .005 smaller than the thickness. I don't know if that is right. I am just concerned with hole alignment between my parts.
I just checked our table, and it only shows 3003 (even though we do A LOT of 6061)
I will check around and see what I can come up with for 6061.
todd
Hoping for Orlando for SWW19, or possibly somewhere in the middle again (We really liked San Antonio and Dallas).
Scott Baugh wrote:
Depending on where SWW is next year you might see me there. I have no desire to go to LA ever.
I did contact one of our shops and what they gave me didn't help me create a bend table or any k-factors. I already have one for Carbon Steel, now I want to add Aluminum since we are doing a lot of work with that material recently. Right now we are just using 6061 plate ranging between .063"-.125" and the radius I have been using is always about .005 smaller than the thickness. I don't know if that is right. I am just concerned with hole alignment between my parts.
At my previous employer we had our own sheet metal shop and bent a lot of galvanized steel and some stainless and some aluminum. You are right to treat these metals differently, but I don't know where you got the information to use a bend radius that is a function of the thickness. For our press brake operations we used the nose radius of the tooling for our inside bend radii. Our rule of thumb was to use a bend radius no smaller than the material thickness. At one point I locked up all the crappy tooling we had and bought new and only bought .063" and .25" nose radius tools. We measured coupons and used a spreadsheet (attached) I had setup to determine the K-factors and we had fantastic accuracy as a result. One BIG caution is to use the measured thickness of the material, not the published values. Our metals never came in at the nominal gauge thickness. When we made this adjustment we were dead-on, less than .005" from nominal on a three-bend part.
Hello,
I prefer to use gauge tables instead of bend tables.
See my reply in this recent post: sheet metal properties
You should have a sample steel gauge table (Excel file) that came w/SW somewhere in one of SW install paths.
Copy it and edit it for aluminum gauges.
You can find aluminum gauge listings on the Internet.
Once you've populated this file with all (most) gauges, contact your fab houses to see what gauges they stock.
Copy the original gauge table and in the copy, delete the gauges your shops don't normally carry.
This will keep your gauge dropdown list short and limited to what's mostly available.
You can, at any time, change the gauge table to another file and select another guage (or another material).
As stated above, check with the fab shops you deal with to see what the nose radii are for their in-house tooling (standard or custom).
Enter these into the radius column. The radii need not be in numerical order, just separated by semicolons.
If you have a default radius in mind, enter that value first for each gauge.
If there's a second favorite radius, put it as the second number.
Probably best to enter any other remaining radii in numerical order.
The k-factor shown is for all gauges, but can be overwritten in the part.
Because of this, you may need to have multiple aluminum files so you're not having to override K when the aluminum alloy changes.
5052 bends a lot easier than 6061 and 6061 with generally require larger nose radius tooling to avoid tearing on the outer radius, so perhaps make 6061's default radii larger.
It is true about the general rule to keep the inner radius at least the gauge thickness, but metal is formed with real tooling not theory.
So you can bend to the tooling nose, usually as air bending, but if the nose is small enough, it'll be coining.
Keep the capabilities of your fab houses in mind while you model.
Also keep in mind that sheet metal is an art and you may not get an exact response to some questions, if the questions (directly or indirectly) ask about the ingredients in the secret sauce.
And develop a good working relationship with them for minimal costs and smooth projects.
Lastly, they know what's feasible so accept all advice with grace as it's for your benefit.
I hope this helps,
Kevin
It shouldn't matter if it varies or not. Most shops will ask for the part file or a .stp version of it so they can generate their own flat pattern out of it which will fit their shop's requirement(The K-Factor). The radius though is up to you and the machinery that will be used. Obviously you won't bend a 2 inch plate with a 1/8'' radius.
Here's an idea of how we work here.
We use 1/8'' Radius for 1/8 and 3/16'' plates.
We use 5/16" Radius for 1/4 and 5/16'' plates.
We use 3/8 Radius for 3/8 and 1/2'' plates
We use 1/2 Radius for 5/8 and 3/4'' plates.
Anything over that is done using another method which is called air bending. I don't quite understand the methodology of it but basically you use a die and depending on your plate's thickness it will force a radius upon it.
Todd Blacksher wrote:
...Hoping for Orlando for SWW19, or possibly somewhere in the middle again (We really liked San Antonio and Dallas).
I know it will never happen, but I would love to see Boston, New York or the perfect destination midway between NY & Boston Hartford.
It was in Boston many years ago. If I recall it was the coldest winter on record at that time of SWW. I don't think they will have it back there again, because there were no activities outside the hotel if recall.
Thanks for all the great info Kevin. I am in no way a Sheet metal guy. I can create it in SW and make it look good, but in the real world that is someone else job. If we had our own break press, then I would take more time to learn the art and the technology. Right now I am barely able to keep my head above water.
FYI: I am using a Sheet metal "Gauge" table for all my Carbon steel. I did found an excel program to calculate my k-factors and they are really close to a few of our fabricators, but that table did not calculate Aluminum. I have searched the web and all I can find is gauges, not a general bend radius with its corresponding gauge. I do understand that I can probably use whatever radius I want, but I would rather have a generalized radius or something someone uses so I am some what correct in my models. I rarely release my models to anyone, because I know the k-Factor probably varies and I fear they will use the model as is.
What I have been told from our fabricators is that the Bend radius has a variance between the Material thickness and the Tonnage of the press. Some of our fabricators find it impossible to use a tight bend radius on a .250" steel and I understand that. So I don't want to just use anything. I am looking for someone that either has aluminum bend table that might be willing to share or can point me in the right direction, since my web searches of not turned up anything of value or I am just flat out not understanding what I am looking at.
Thanks for all your replies, I do appreciate it!
Scott
Here is a start-up you could use to fill your information.
K-Factor is where you will enter the K-Factor your want
Gauge N° can display anything, it'll be what will display in the rolldown menu.
Gauge Thickness is the thickness of the sheet.
Available Radius is the radiuses you will use.
Keven has given you a bunch of info on how to build the table, so you can read his post while building it if you need help.
Thanks Alex, I will give it a try!
Here's a little more info -
The K Factor is dependent on actual material thickness and equipment used. It'd be better for the fab shop to tell you their K factor.
That's very true and your right, but that means I would have to have a separate table for each fab company we use. Then depending who we used then I would have to go through and change that for every file. That's why I was hoping there was something more general... doesn't seem to be the case though.
I think that Alex Lachance gave you some good info - Using a K-Factor around .33 is a good place to start.
(Some of our K-Factors are around .38 - This is using .100" - .190" thick 3003 with a .125" bend radius.)
As I stated, don't worry about outside companies, worry about how you work inside your shop.
If you send the drawing to be made somewhere else, they will most likely ask you for the part or a step in order to rebuild the flat pattern to fit their standard.
Thanks everyone, if I have any other questions I will post back here... I think I can get something put together from all this great information... It would be a lot easier if we had our own press brake, but it is what it is.
Thanks everyone!
If you don't have a press break, just use what I sent you as a start up and use a radius that matches your thickness, that should work at most places.
Hello,
You're quite welcome.
Please remember, the k-factor for you doesn't have to be too precise.
It only affects the flat pattern dimensions.
As long as you dimension fully and correctly, it's up to the fab house to determine the required bend allowance to achieve your dimensions per material, thickness, bend radii, bend angle, etc.
By "correctly", I mean dimension to the sharp corner (use the intersection option (right-click) when dimensioning to insert the point):
This shows the final dimension that's required for the part.
They will compute how much extra material is required to turn the corner.
Also, you have the choice of (5) virtual sharp display styles when you insert one of these:
Cheers and Merry Christmas!
Kevin
Rumor has it that SWW will be back in Texas in 2019...
Steve C
Steve Calvert wrote:
Rumor has it that SWW will be back in Texas in 2019...
Steve C
That would be sooooooo awesome!
In my experience, fab shops ask for a flat pattern DXF, not the model file
I guess it depends on the place then. In 2012 we started with DXF's and then we instated some sort of quality control to make sure everything coming from outside was top notch. That's when they started asking for steps. It's really only for bent plates though, if the plate doesn't have a bend in it they'll take a DXF over a step any day of the year, saves a lot of time.
Edit: I am dealing with plates that can rage from 2MM to 3 inches of thickness, perhaps it depends on what you work with too. I doubt a 16GA flat pattern will change much when you modify the K factor but with a 1 1/2" thick plate, the flat pattern can vary a lot more.
Hello,
I prefer to use gauge tables instead of bend tables.
See my reply in this recent post: sheet metal properties
You should have a sample steel gauge table (Excel file) that came w/SW somewhere in one of SW install paths.
Copy it and edit it for aluminum gauges.
You can find aluminum gauge listings on the Internet.
Once you've populated this file with all (most) gauges, contact your fab houses to see what gauges they stock.
Copy the original gauge table and in the copy, delete the gauges your shops don't normally carry.
This will keep your gauge dropdown list short and limited to what's mostly available.
You can, at any time, change the gauge table to another file and select another guage (or another material).
As stated above, check with the fab shops you deal with to see what the nose radii are for their in-house tooling (standard or custom).
Enter these into the radius column. The radii need not be in numerical order, just separated by semicolons.
If you have a default radius in mind, enter that value first for each gauge.
If there's a second favorite radius, put it as the second number.
Probably best to enter any other remaining radii in numerical order.
The k-factor shown is for all gauges, but can be overwritten in the part.
Because of this, you may need to have multiple aluminum files so you're not having to override K when the aluminum alloy changes.
5052 bends a lot easier than 6061 and 6061 with generally require larger nose radius tooling to avoid tearing on the outer radius, so perhaps make 6061's default radii larger.
It is true about the general rule to keep the inner radius at least the gauge thickness, but metal is formed with real tooling not theory.
So you can bend to the tooling nose, usually as air bending, but if the nose is small enough, it'll be coining.
Keep the capabilities of your fab houses in mind while you model.
Also keep in mind that sheet metal is an art and you may not get an exact response to some questions, if the questions (directly or indirectly) ask about the ingredients in the secret sauce.
And develop a good working relationship with them for minimal costs and smooth projects.
Lastly, they know what's feasible so accept all advice with grace as it's for your benefit.
I hope this helps,
Kevin