Sheet metal brakes are sometimes huge
machines that are not always portable or
affordable, so let's look at some other
methods to bend sheet metal without a brake.
This is Cosador, Johnathan here. If
you ask most people how to bend
sheet metal they'll say that you need a
brake, and that's not the one that you
sit down and drink a refreshing beverage
of choice, they're talking about a pan
brake a press brake or a metal folding
machine. which in this case, I'm going to
do without. I'm going to do it by hand or
with minimal tools, but before we start
I'm going to answer a few questions and
tell you a few things to consider when
bending sheet metal.
So, what is a good bend?
a good Bend is defined by the
radius of the bend, how straight it is,
and if it meets the required angle.
In this case, I'll be clamping the steel
sheet and bending it, in order to make a
bend that's as tight and sharp as
possible, I need to look at the radius of
the bend, the bend is always rounded and
the radius is the determining factor of
how tight or sharp the bend is, and the
radius of the bend highly depends on the
clamping material, timber is not hard
enough to make a tight bend and I
require something harder like steel. The
inner radius of the bend is dependent on
the radius of the clamping material and
the outside radius is equal to the
clamping material plus the thickness of
the sheet metal being bent.
So a piece of angle steel with a sharp edge is ideal
for a 90 degree bend.
This might be common sense, but before you touch
anything consider safety, sheet metal can
be sharp and cause permanent injury, so
think about protecting yourself because
life is harder without your fingers, your
eyes or your blood.
I'm going to bend .55mm Zincalume steel sheet, which
is roughly double the minimum thickness
of this type of product and it's about
as thick as I would want to go by hand,
therefore it should be a good measure of
the different methods of bending thinner
sheet metal.
Okay, marking up.
Marking up is essential because I need to know
where my bend is going to be, I draw a
line with a marker in each of the places
I wish to bend, paying attention to the
edge of the line as an absolute measure
where I intend the inner radius of the
bend to be as close to zero as possible.
Because each of the methods are based on
force, I need to clamp this well. I
sandwich is steel sheet between
rectangular tube and rigid angle, which
are both longer than the sheet that I
wish to bend. At the same time, lining up
the edge of my marking, I make sure that
the two clamps are over the steel sheet
but not interfering with the direction
of the bend.
Okay, let's start bending some metal.
Method number one, by hand. With
everything clamped tightly, I get a good
grip and from as close to the intended
bend as possible
I push upwards, refining the bend and
lowering the position of the push until
I physically can't push it any more, I
unclamp and refine the bend. It's not
perfect but the job is done.
Method number two, with a hammer.
with everything clamped, I give a good push by hand like
the first method, then on the bend, I give
it a soft hammer, slowly refining the
edge, moving along the bend, trying to
keep the hammer hits as tidy as
possible, it has a few dents in it here
and there but it's definitely a tight
edge.
Method number three, score and bend.
So, I put down a flexible material that
will give a little during scoring,
I put the sheet metal on top then a rigid
straightedge and I clamp it down, leaving
enough room between the line and the
straightedge to accommodate a scoring
tool, in this case I'm using a
screwdriver because the steel on the
screwdriver is harder than the sheet
metal. I score the sheet metal in
multiple passes to get a score that's
close to quarter thickness of the sheet
metal, I want to make a weakened line
where the bend favors that point but not
significant enough to compromise the
strength of the sheet, then I
clamp it the same as the others and I
push by hand as close to the intended
bend as possible, I refine and then it's
done.
Method number four, with the roller.
for this one, I need to make a tool. I
need a couple of trolley wheels and a
bit of timber. The trolley wheels should
be plastic or hard rubber, they should be
square on the edge and rounded in the
middle for the best performance and
simply, I'll pre-drill and screw them to
the timber in an inline configuration.
With the sheet metal clamped, I help it a
little with my hand due to the thickness
of the sheet, then I roll the roller as
close to the intended bend as possible
the roller works by pushing on a small
area like the hammer, however it doesn't
dent and warp the metal quite as much. I
continue to refine until the bend is
sufficient and once again it's done.
Okay, evaluation time. Personally I think each of these methods have a purpose.
I would bend by hand if that were my only choice
and the sharp radius isn't absolutely
necessary, I would use a hammer if I
wanted a really tight bend, but I had
time to refine the surface afterwards,
I would score an bend if I wanted to
control a long hand bend,
but I didn't have a roller or the
material was too thick, providing that I
could protect the score mark from
corrosion, and I would use a roller if I
was working with thinner sheet that was
going to be used externally, but which is
best really depends on the situation and
the operator.
Working with metal can be tricky, especially if it needs to be precise.
Metal remembers all your mistakes and doesn't easily forgive,
but with practice it becomes predictable,
and if any of these methods were useful to you,
please like and subscribe and keep
watching if you want to see bigger
projects where we put all of this
together, if you want me to go into more
detail or make a video about something
else just drop a comment below,
and remember guys,
Break It til You Make It!
and I'll see you next time