Your method for bending steel pipe will depend on the diameter of the pipe you are using and the acceptable amount of deformation in the process.
Method #1: Slice the Pipe
The easiest way to bend a steel pipe bend is to make partial cuts through the pipe at different intervals. Once the pipe has been properly bent, you can weld it shut. This is a simple method, though it is not always the first method of choice because it produces an end result that does not look as clean.
Method #2: Table and Jig
Bolt a steel-top table to the floor. You can try to use another type of table (like plywood), but it may not provide enough resistance to the steel pipe. Use a table when you are bending pipe between 1 and 2 inches in diameter, but no larger.
Bolt a jig to the table with steel pins, and bend the pipe around and over the jig accordingly.
Method #3: Sand
Use sand to prevent the pipe from becoming warped or misshapen during the bending process. Place baked or dried sand in the pipe, as this will prevent tight bends and kinks. Make sure the sand is packed tight, and place caps on the end to keep it inside.
Then you can secure the pipe in a vise, bending it at the desired point and angle. If you are applying heat to bend the pipe, drill holes in the caps to prevent an explosion.
Method #4: Cold Bend
Bend a pipe using a hydraulic pipe bender or a Greenlee electric bender. These methods only work with pipe that is 2 inches in diameter or smaller.
Method #5: Ram Bending
This is a simple and cheap pipe and tube bending method. Using a ram bender, the tube or pipe is secured at both ends and rammed at the bending point to create the fold. The downside to this method is that the pipe can be deformed in some situations.
Method #6: Ring Roll Bending
Pipes with large circumferences are best bent by way of ring roll bending. Three rolls, each on an individual shaft, roll the pipe through while exerting pressure to deform the tube into the proper shape.