How To Hem Sheet Metal By Hand

The wuko 4000 will hem bends on long pieces of metal with a maximum bend of 1 1.

How to hem sheet metal by hand.

Now that you know your bend allowance take your protractor and draw a clear line with your marker across the point at which you will bend your sheet metal. That of the gap. The first bend uses the channel as a v opening to air form the bend. A two stage hemming die works by using a deep channeled die and an acute sword punch.

The wuko 3200 duo bender is ideal for long straight bends of depths up to 8. To establish the hem bend line add the two outside dimensions up to the hem then subtract half the hem elongation allowance and a full bend deduction for the inner 90 degree bend. The bend is flattened and the extra piece is removed. To establish the inner smaller radius 90 degree bend line subtract half a bend deduction from the outside dimension of the flange.

Mark your bend lines. I built some custom doors for a bike shed. In the second stage the punch slides into the channel as the punch is closed and the edge of the punch is used to flatten the sheet metal. I wrapped them in metal for durability and in this video i show how i bent the trim coil used on those doors.

This does mean that the tonnage required will be the same as a closed hem. Hem is created by placing a shim of material of the correct thickness. Then use your bend allowance to draw your second bend line the intervening distance between your bend lines bend radius.