What steel for a plate bender die?

[BrokenBiker]

I'm calling it a die but not entirely sure that's right, but either way, I'm making a little plate bender that will utilise the 20t bottle jack off my larger press.

What would a good steel choice be for the business end end of it? The part that actually presses down on to the piece being bent?

I've got some heavy duty angle iron as the forming piece but at the moment just using a bit of 10mm hot rolled plate cut to size and ground to a point, then a small radius ground on the tip for a smooth bend.

Likely won't ever bend anything more than 3mm. May e 5mm with a bit of heat if needed.

I have in the scrap bin a shock absorber with a decent condition chrome plated rod, a complete driveshaft that I assume would be a tough steel, some knackered cheapo wood chisels, and a fair few cheap hss drills that were bent before I'd even tried to use them.

Or i can buy a bit of whatever grade steel needed from rapid metals

 

[pressbrake1]

There’s very limited choice with flat sections at present. Also you only need a small amount.
Due to low pressure and as long as your not going to put durbar or round into it use whatever you can get

 

[BrokenBiker]

There’s very limited choice with flat sections at present. Also you only need a small amount.
Due to low pressure and as long as your not going to put durbar or round into it use whatever you can get

Only plan on ever using it to make brackets out of mild steel or ally sheet, maybe the od bit of thin stainless...if i ever bend round bar i generally just do it hot in the vice as it's easy to handle.

This bender will only have a working width of 150mm for small brackets and odd shaped pieces when doing repairs on gates and my mates bmw. Easier to take a small bender with me than try and guess what's needed before hand

 

[Dcal]

I made a former to bend 600mm long 10mm stainless plate in my 50t press.

I knew I wouldn't have a chance at 10mm so I cut part way through and it bent 5mm no bother
It was made out of whatever I had in the scrap pile and was all probably mild steel.

Post in thread 'Stovax Riva Repair'

Nov 18, 2019

The last couple of sets of baffles I installed were made from mild steel and didn't last that long.
This time I decided to use 5mm 316L stainless, reckoning they should last a good bit longer.

I cut the rough sizes I needed with the plasma and cut to final size with the 9 inch grinder.
The plan was to then cut part way through the plates where I needed a fold and bend them on my folder.

Even with only 1mm of steel left uncut, the folder didn't want to play ball, the sheets were too thick to clamp properly and I was going to brake it if I persevered.
A new...

• Dcal

• 

For what you are doing any grade steel will be fine.

 

[BrokenBiker]

I made a former to bend 600mm long 10mm stainless plate in my 50t press.

I knew I wouldn't have a chance at 10mm so I cut part way through and it bent 5mm no bother
It was made out of whatever I had in the scrap pile and was all probably mild steel.

Post in thread 'Stovax Riva Repair'

Nov 18, 2019

The last couple of sets of baffles I installed were made from mild steel and didn't last that long.
This time I decided to use 5mm 316L stainless, reckoning they should last a good bit longer.

I cut the rough sizes I needed with the plasma and cut to final size with the 9 inch grinder.
The plan was to then cut part way through the plates where I needed a fold and bend them on my folder.

Even with only 1mm of steel left uncut, the folder didn't want to play ball, the sheets were too thick to clamp properly and I was going to brake it if I persevered.
A new...

• Dcal

• 

For what you are doing any grade steel will be fine.

That's good to know, cheers. 10mm plate it is then

 

[Redsailor]

Here's my set up. Used a piece of 9mm x 65mm mild steel bar stock as that's what I had. Press is home built job with a 20 ton ram. The important thing is the "air gap" or space in the bottom die.

Bend is a bit of 3mm plate about 100mm or so long as a test piece.

(Click on pics to enlarge )

 

[BrokenBiker]

Here's my set up. Used a piece of 9mm x 65mm mild steel bar stock as that's what I had. Press is home built job with a 20 ton ram. The important thing is the "air gap" or space in the bottom die.

Bend is a bit of 3mm plate about 100mm or so long as a test piece.

(Click on pics to enlarge )

Hadn't considered a gap at the bottom, just assumed pushing the plate down into the angle iron would do the job...I have some hefty round stock I could use instead of the angle iron

So are those 2 bits of bar spaced at any certain distance or is it just wide enough to let the tool pass through?

 

[Redsailor]

Hadn't considered a gap at the bottom, just assumed pushing the plate down into the angle iron would do the job...I have some hefty round stock I could use instead of the angle iron

So are those 2 bits of bar spaced at any certain distance or is it just wide enough to let the tool pass through?

If the bottom piece is an angle similar to the top die the pressure required would be quite high, you are in to proper press brake territory. Mine was just a "looks about right" guess. There are charts on the web that can show you the tonnage per length / gauge of material for air gap spacing on the bottom die. Hope this helps.

 

[Morrisman]

Hadn't considered a gap at the bottom, just assumed pushing the plate down into the angle iron would do the job...I have some hefty round stock I could use instead of the angle iron

So are those 2 bits of bar spaced at any certain distance or is it just wide enough to let the tool pass through?

If you’re after a nice 90° bend you’ll have to go a bit deeper to allow spring back of the metal being bent. The 2 bars method allows some fine tuning on that front.

 

[BrokenBiker]

Thanks all, will cut some bar and just eyeball it for now, can always cut the welds and reposition if needed

 

[frank horton]

I just use a bolster chisel fixed into my fly press, with a piece of angle iron used to form the V.....I just cut the battered / bruised end of the chisel off.....
placed as a V on some heavy flat plate, with some odd bits of rebar to stop the flaps bending...
I reg make 90º brackets around 75-100mm wide out of 4-5mm plate...

 

[gaz1]

i like the swag press brake make the former and reduce using angle iron