Bending plate steel to odd angles

[catalytic]

I would like to put a obtuse angle bend (135° would work) into a piece of 1/4" or 5/16" thick x 7" wide mild steel plate. This is probably a piece of cake for you fab guys, but I've never seen anyone do it in a machine shop (we're currently limited to a little brake for sheet metal and a press brake on a 50ton H-frame Dake press for putting 90°-only bends in pieces like mine).

What are the best options/machines/methods for getting this done?

The radius of the bend doesn't matter much in this case, although smaller is better. I could cut and weld it, but that wouldn't look as pretty and this piece will be seen (it's a bracket to hold switches and controls for a Max 16" disc sander I'm restoring)

 

[zkling]

Just do it in the press brake and stop before it gets to 90°. If you use an angle gauge and take a base measurement you can get it very close.

 

[kkroger]

Do the math on your angle drop a piece of round bar in the bottom of the press brake die, for a stop... press it down to that point and you should be good, you may need to use a slightly smaller piece of bar so you can account for springback... You can model the angle in CAD to find the distance you need to move the apex of your bend too.
if you need to bend several...

 

[lmwilco1]

Here is a link to what you need, you can request the spreadsheet and it will tell you the size of round bar required.

Louis

http://rick.sparber.org/BAG90.pdf

 

[mike13u]

Just do it in the press brake and stop before it gets to 90°. If you use an angle gauge and take a base measurement you can get it very close.

This^^^

The Swag Off Road press brake that is reviewed in another thread under 'Fabrication & Techniques' right now will handle that job easily.

 

[Tink]

I know you don't want to cut and weld it but would it help to grind a groove along the bend line on the inside of the fold then weld it after you make the bend?

 

[srmofo]

.25 sounds really heavy for a switch bracket

 

[vhol5]

.25 sounds really heavy for a switch bracket

^^^^^^^^This^^^^^^^

 

[kkroger]

^^^^^^^^This^^^^^^^

I generally don't question someone's choice of materials... BUT.
I can't imagine why you would need 1/4 - 5/16! I would probably use 18 Ga for that and just bend it on the box and pan brake...
But if you gotta go with the thick stuff see above about using the press brake...
figure your angle and drop a round bar in there and go for it.

 

[catalytic]

Thanks for the replies, guys.

.25 sounds really heavy for a switch bracket

I agree, although it probably sounded about right to the war-era patternmakers who put 350lb of iron in my 16" disc sander. Thing is, the bracket has to stick up over a foot from where it attaches in order that the switches on it are above the disc, and I don't want it to look weak or wobble every time i hit a switch. Due to front-to-back clearance where it's going, it would be a pain to use angle/channel/tube stock, so plate steel it is. The bends I'll be putting into the plate are not turning it into angle iron, but instead bending it around the front of the motor to address this clearance problem (will post a picture when I get it done).

 

[Kevin54]

Like Mike13U stated. Just stop it before it gets to 90 degrees. Piece of cake if you can do 90, you can do 135 very easily.

 

[astroracer]

I'm looking at your drawing and I see a 45deg bend. 22.5 degree's on each side if it's laying flat on the press brake die. You have the 135 dimensioned but I see the 45 degree on the LH side as the actual bend. If I'm not seeing it right I guess I need more clarification.
Mark

 

[jimgood]

I'm looking at your drawing and I see a 45deg bend. 22.5 degree's on each side if it's laying flat on the press brake die. You have the 135 dimensioned but I see the 45 degree on the LH side as the actual bend. If I'm not seeing it right I guess I need more clarification.
Mark

Sure. When bending a piece of flat plate (180*), you would be bending the plate 45*. But we knew what he meant.

 

[astroracer]

Sure. When bending a piece of flat plate (180*), you would be bending the plate 45*. But we knew what he meant.

Excellant! I was just wondering because this is a simple 22.5 degree bend on a press brake. I see a lot of 90 degree comments when he will be nowhere near that.
Mark

 

[rdn2blazer]

You do not need a press break to bend this. Do it on a heavy and stationary work bench. Clamp it down tight with the bent line at the edge of the table facing down. Get two of the largest tapered handle cressent wrenches from Harbor Freight. Tapered handles are best for adding a piece of pipe for leverage if necessary. HF has 24" cressent wrenches with tapered handles. I use them ALL the time for bending.

Have a angle protractor ready to go. Start bending downward a little at a time checking as you go. Set your protractor first so you have an idea about how far you need to go. Use it as a reference. Get your bend close, then fine tune it into perfection. Done. Only tools needed are a good heavy work bench, two big cressent wrenches, two C clamps, and a angle protractor. Most garage guys have these tool. Not everyone has a press brake in their garage. Thats how I bent these diamond fish plates too. 1/4 thick bent by hand.

 

[kkroger]

But if your have a 50 Ton Press Brake at hand... use it...

 

[rdn2blazer]

But if your have a 50 Ton Press Brake at hand... use it...

Well heck yeah! lol I have only a 15 ton and I will use it too before bending by hand. I think I bent the stuff pictured before I had my 15 ton press.

 

[Zeke]

You do not need a press break to bend this. Do it on a heavy and stationary work bench. Clamp it down tight with the bent line at the edge of the table facing down. Get two of the largest tapered handle cressent wrenches from Harbor Freight. Tapered handles are best for adding a piece of pipe for leverage if necessary. HF has 24" cressent wrenches with tapered handles. I use them ALL the time for bending.

Have a angle protractor ready to go. Start bending downward a little at a time checking as you go. Set your protractor first so you have an idea about how far you need to go. Use it as a reference. Get your bend close, then fine tune it into perfection. Done. Only tools needed are a good heavy work bench, two big cressent wrenches, two C clamps, and a angle protractor. Most garage guys have these tool. Not everyone has a press brake in their garage. Thats how I bent these diamond fish plates too. 1/4 thick bent by hand.

You were bending tabs. 7" wide is a whole 'nother ballgame. But your method would work with heat.

 

[rdn2blazer]

You were bending tabs. 7" wide is a whole 'nother ballgame. But your method would work with heat.

In the first few pictures yes, but that diamond fish plate is 8" tall X 1/4 thick to match the 8" x 2" steel rectangle tube I built the bumper out of. Only thing I did different from the pictured bending was add cheater bars on my cressents. And not 6' but maybe 2' extra for leverage. Been bending things like this for years. I made 2 bends in a 30" wide X 1/8 plate of 316 stainless to 45 deg using a similar method to make a heat shield for a jet engine once. That took some leverage. It was thinner of coure but at 30" wide thats some material to bend.

 

[catalytic]

You do not need a press break to bend this. Do it on a heavy and stationary work bench. Clamp it down tight with the bent line at the edge of the table facing down. Get two of the largest tapered handle cressent wrenches from Harbor Freight. Tapered handles are best for adding a piece of pipe for leverage if necessary. HF has 24" cressent wrenches with tapered handles. I use them ALL the time for bending.

Have a angle protractor ready to go. Start bending downward a little at a time checking as you go. Set your protractor first so you have an idea about how far you need to go. Use it as a reference. Get your bend close, then fine tune it into perfection. Done. Only tools needed are a good heavy work bench, two big cressent wrenches, two C clamps, and a angle protractor. Most garage guys have these tool. Not everyone has a press brake in their garage. Thats how I bent these diamond fish plates too. 1/4 thick bent by hand.

^^ Awesome. I have done this to 1/8" and 3/16" x 1.5" bar stock, but would not have occurred to me that you can get enough leverage to do this to more serious plate steel. While I'll probably use the shop H-frame, this is a great trick to know, esp. if there's a torch nearby.

 

[rdn2blazer]

^^ Awesome. I have done this to 1/8" and 3/16" x 1.5" bar stock, but would not have occurred to me that you can get enough leverage to do this to more serious plate steel. While I'll probably use the shop H-frame, this is a great trick to know, esp. if there's a torch nearby.

I did bend both pictured cold. Have a torch but for the mild bends like this it's not really needed.

 

[All]

You do not need a press break to bend this. Do it on a heavy and stationary work bench. Clamp it down tight with the bent line at the edge of the table facing down. Get two of the largest tapered handle cressent wrenches from Harbor Freight. Tapered handles are best for adding a piece of pipe for leverage if necessary. HF has 24" cressent wrenches with tapered handles. I use them ALL the time for bending.

Have a angle protractor ready to go. Start bending downward a little at a time checking as you go. Set your protractor first so you have an idea about how far you need to go. Use it as a reference. Get your bend close, then fine tune it into perfection. Done. Only tools needed are a good heavy work bench, two big cressent wrenches, two C clamps, and a angle protractor. Most garage guys have these tool. Not everyone has a press brake in their garage. Thats how I bent these diamond fish plates too. 1/4 thick bent by hand.

@rdn2blazer
rdn2blazer

What is the name for the type of C clamps that you are using?

I would like to find some, but of course simply searching "C clamps" reveals the far more common type that are not as robust as the ones that you show in your photo.

 

[imagineer]

Might be late to the party, but for a recent project building new bumpers for a Jeep from 1/8" steel, I used a HF 20T press and their press brake tool.

To ensure the correct bend angle, I used a magnetic digital angle gauge and targeted 1/2 the required angle. It took some 2nd and 3rd presses to be able to sneak up on the target angle, but it worked great.

 

[LXCam]

@rdn2blazer
rdn2blazer

What is the name for the type of C clamps that you are using?

I would like to find some, but of course simply searching "C clamps" reveals the far more common type that are not as robust as the ones that you show in your photo.

/me nudges the All man. 10yr old thread and blaze aint shown his face in 6 years.

I’m just saying

 

[Copymutt]

Just did that yesterday w/ 3/8” square plate. My no cost brake rotor forge made precise butter bending a piece of cake. Cooled in water to retain hardness.

 

[All]

/me nudges the All man. 10yr old thread and blaze aint shown his face in 6 years.

I’m just saying

It doesn't matter to me if blaze is absent... the photos he posted are still present.

I actually thought about sending a PM to rdn2blazer, because of the age of the thread... but then realized that someone else who is currently active may recognize the type of C clamp in the photo, and be able to answer in blaze's absence.

It isn't that I haven't seen that type of C-clamp before... it is now I would like to obtain similar C clamps, but do not know the terminology for that type, so as to better narrow down the search results for them with the right keyword.

If older threads had no value, Ryan could save server space by deleting them. The entire point of carrying an archive of content is so that it can be referred to over and over again, perpetually creating forum traffic without any additional work. The resurrection of a thread in fact inspires new content to be created, which in turn, deepens the archive of interesting posts that serve as references for new readers for the next 6 years, and perhaps 6 decades.

If you know what type of C-clamp that blaze was using, I'd appreciate the education.

Thanks for your interest.

 

[tom in nh]

It is called a bridge clamp.

 

[dscheidt]

It is called a bridge clamp.

If you’re looking in a catalog, they’re probably called heavy-duty or heavy-service.

 

[rvieceli]

@All

Here you go:

https://www.zoro.com/wilton-c-clamp-2-38-steel-extra-hd-12-500-lb-2-fc/i/G4972545/

Ron

 

[tarbellb]

@All when looking for a education on something like this, I always see what www.mcmaster.com has to offer
pics, descriptions, variations, etc....

Here you go, found in clicks

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com