A little time spent to set up tooling for a future job can save loads of time, material, and stress when you eventually get around to making the item.
Choose the Former Diameter Carefully
The former diameter should be roughly three to four times the material thickness. This would apply to bending steel bars, and you may need to go slightly larger for harder alloys as the outer face of the bend could crack. You should check if the required radius can be achieved with the former you have for the specific job, before committing material.
Match Tooling Material to the Workpiece
When bending mild steel, stainless steel and other similar materials, hardened steel tooling is preferred over softer tooling as it will not deform under load. Aluminium, copper and other similar profiles can be bent using a lower hardness former to prevent surface marking.
Pick the Right Support for the Section
For hollow sections, like tubes or H-beams, the best way to bend them is to add a support roller or close-fitting die to the tooling to ‘wrap’ the section. The solid bar is much easier to bend than hollow sections and for these, a V-die or a saddle can be added to the tooling to give a very clean bend, especially if the width of the bar is to be matched.
Allow for Springback in the Tooling Geometry
Metals tend to spring back after they have been bent and then released. As a result, most benders are set up to over bend (i.e. bend more than required) and then allowed to return to the required angle after the metal has been released from the machine.
Check Registration with the Machine Spindle
Finally, ensure that any former or die is correctly bored to fit the spindle on your bending machine. Bending Machines is covered in more detail at https://www.cotswold-machinery-sales.co.uk/euromac-bending-machines/horizontal-bending-machines/. The safe use of machinery guidance provided here also highlights a problem in many workshops: poorly secured tooling.
A few minutes spent selecting the right tooling will save hours of wasted material.