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