How to bend square tubing without a bender - metal fabrication

Sharing buttons:

I'm going to show you how to bend square

tubing without a bending tool it's gonna

be awesome what you will need is a chop

saw and a welder and a calculator that

can do multiplication of Pi and yeah and

maybe some stuff to draw with please

note bending metal like this will likely

reduce the strength of the metal versus

just bending it with like a normal

bender but if you're doing something

like I am where it's a non-load-bearing

gate frame or like a light load-bearing

gate support you should be just fine

this is a technique that I developed

after taking a course in high school

called geometry and I even used this

method back then to build stuff with

large bins in it and it was square

tubing from here I'm going to do a quick

overview and then into this video with

some more precise and boring math for

those who want to know the deets

essentially with any bent piece of

tubing that is an even Bend there's an

outer and an inner circumference that's

created and what you want to do

beforehand is measure it out know the

difference between the two circumference

is and then make it so by cutting a

portion of the inside of tubing like the

bend it's the portion that you cut out

is a specific amount of length in total

that is evenly distributed across

several cuts and then yeah the middle

could just easily just bend in a shape

and you weld it up okay before I go a

little deeper here let's do a quick

preview of a tool that I bought at Home

Depot which is now a sponsor run or

Israel be the ryobi blower it's got what

it takes to blow life back into the

party do you hang out and have bonfires

with friends and would like to light

things up to the next level

a Ryobi blower is just what you need

grass clippings by day and bonfires by

night this Ryobi blower can bring the

heat whoosh so you saw me do a large bin

I also end up doing a smaller one that

the smaller one was much easier to do

the math for because the total diameter

of the circle that could fit within the

bend could also fit within like arm's

length unlike the the gate one the big

gate one

if you saw my welder review there's this

little bit of me trying to fix my older


yeah and realizing that just buying a

new one made more sense

check out my welder review linked in the

I in the corner of the screen if you

have not seen it yet and if you're

curious and you want to maybe look into

a low-cost Walter it costs a little over

a hundred bucks

it's like 120 I think okay so to the

math I'll show you how to do the math

with a really big complex Bend and also

the smaller one as well I ended up using

a computer for the large Bend because I

needed to find the outer and inner

diameter and circumference of like an

enormous circle do you need a computer

not really but if you have a very large

Bend like this one you'll need to draw

it and like draft it and protract and

stuff on graphing paper and be precise

for the large bin I took a picture of

the fence where I wanted to put the gate

and I'm able to scale portions of the

image and illustrator precisely measured

in inches and yeah I'm not gonna go too

deep into that part after that I drew a

two-inch frame over the image of what I

wanted the gate to look like and then I

drew an enormous circle over the gate

adjusting its size to give it like the

bend that I wanted to see you know like

the curve when you draw like this it's

like a very rude style of computer

assisted drafting or CAD and in either

way you get a WYSIWYG situation what you

see is what you get we see WYSIWYG if

the gate frame looks like this on the

computer then it will look like this in

real life

and in order for that to be true you

just can't mess up measurements or cuts

like anywhere and also you can't make a

mistake while you're drawing after that

I measure the angle from each point

where the bend portion met the square

portion of the frame you can see that I

cut out a piece and that represents a

thirty five point nine degree portion of

the circle remember what you see is what

you get and I see a thirty five point

nine degree piece of pie YUM I

I mentioned that's the there's an inner

and outer circumference to the bend and

now I will draw some and talk to you

about math just watch it through without

stopping first then go back don't pause

until I'm done showing you the math or

you might get like stuck in a brain fart

that just won't stop smelling so just

hold it watch it all the way through

then go back and pause accordingly

seriously when you when the math comes

together in the end and that initial

loop closes you may have an aha moment

that you're depriving yourself of if you

start pausing early on so we have the

piece of metal that we need to bend it

has the outer and the inner portion okay

and we need to find some stuff out about

this so we have a circle on the outside

a circle on the inside the the larger

one from here to here is four hundred

and three inches the inner one because

we take away two here and two here is

minus 4 so 399 from here to here now to

get the entire circumference of both of

these you times these by PI and so I've

done that here of the smaller one but

1250 3.49

all those numbers are inches sorry if

you're not from America

too bad metric would be so much simpler

I don't know why we do this and then of

the larger circle we have 1260 6.06 so

those are the circumference of the outer

and inner circle that gives us the

distance all the way around in inches

but what we need is only this piece

right here we need that length and that

length which this is a thirty five point

nine degrees thing so I'll show you how

to do that take one of the circles

circumference let's take that one and

know that that equals three hundred and

sixty-eight degrees

and then we want to know what this

number is

we know the degrees but know what the

number is and so you take this times

that equal it out my calculator and

divided by that you will get one hundred

and twenty five point zero zero some

other numbers but that's how many inches

that this piece right here is okay

pretty cool math all right now and then

we've got the one hundred thousand two

hundred sixty six six to 360 thirty five

point nine you cross multiply and divide

and that gives you one hundred twenty

six point two five so this is the outer

length one twenty six point two five so

we cut the piece of metal that length

and the inner length is 125 it's 125

your - those out and you get 1.25 now

1.25 inches that is when your the

difference between this piece and this

piece so you have to evenly make cuts

along this and I actually have to draw

the cut all the way to the wall not

through it all the way to it whoa dang

it and that is figured out by doing this

which is we have to okay so we have to

cut that out right so got your 1.25

inches you need to cut out the width of

my blade is what has to be considered

here and most chop saws are by the needs

of an inch which in decimals is 0.125

which if you notice those kind of match

up that's because it's ten so ten cuts

will end up hogging out an eighth of an

inch each time which brings it to 1.25

inches gone now here's the piece of

metal that we cut one hundred twenty six

point two five and we need to make the

cuts so what you have to do is you have

to add one extra cut you take this

divided by

the number of cuts excuses 11 and then

that gives us one cut every eleven point

four seven seven two inches so little

under half of an inch if you times that

by 10 I'll give you one hundred fourteen

point seven which should then leave you

with this remaining anyway yeah one two

three four five six seven eight nine ten

there now every single space here is

eleven point four seven inches and after

you cut I you make your cuts like this

deep each time no all the way through of

course but you make it up to the wall

and then you can just bend it and so

that is how we do the math that's I hope

that was bearable I hope you're not lost

with the math the timestamp on the

screen is where you can like school back

and where the math starts and also I'll

link it in the description it'll say

like start over the math portion or


yep well that's all it takes I hope that

helped see you later Internet are you

are you still there okay okay I've got

some jokes

you haven't killed the video so I've got

some jokes what the what is the

thermometers favorite part of a pie

chart the various amounts of degrees do

because of thermometer yeah

oh I got another one what is the

thermometers favorite part of college it

could choose for many degrees this is

really bad