A sheet metal brake is a very handy tool for metal workers, but is not found in many home hobbyist shops. Small sheet metal brakes can be ordered from the Internet including the specialty catalogs Northern Hydraulics. However, this approach is usually cost-prohibitive for the occasional user. By following the steps outlined in this article you can make your own sheet metal brake at a very low cost using materials from your local hardware store. Mount the assembly to a bench or other suitable stand. The brake pictured is mounted to the top of a bench-top hydraulic press.
Measure and cut three pieces of a 2-inch-by-2-inch-by-1/4-inch angle iron. It must be 30-inches long.
Drill two 1/2-inch holes in two of the pieces cut in step 1. The hole should be located 3/4-inch from each end and 1-inch from the edge.
Weld a 7/16-inch coarse threaded nut on the inside of the angle, centered carefully under the drilled hole. Clamp the nut in place with a 1-inch long 7/16-inch bolt. Weld another nut in the same manner on the opposite end of the same piece.
Place the 1/8-inch pipe nipples on the 1/4-inch steel rod. This will be the hinge.
Align the angles and weld the pipe nipples for the hinge. Weld one nipple to the angle iron with the nuts welded to it, the next to the undrilled angle, and alternate welding the remaining tubes to form a hinge. Be careful not to weld two tubes together.
Center the piece of 1/2-inch pipe on the undrilled angle iron and weld it in a perpendicular position from the back of the angle.
Thread the two remaining 7/16-inch nuts on the 3-inch long bolts. With the second piece of drilled angle iron this will be the clamp to hold the sheet metal to be bent.
Position the sheet metal to be bent between the two drilled angle iron pieces. Tighten the bolts with a wrench to firmly clamp the workpiece.
Make a mark on your sheet metal where the bend should be located. Align this mark with the edge of the clamp bar.
Make the bend by lifting up on the pipe nipple handle. A short extension can be fit in the nipple for more leverage on heavier stock.
Check the angle of the bend and if correct, loosen the clamping bolts to remove the workpiece.