08-03-2015, 12:37 AM
You're right, a common slip roll won't work @ 10mm. But, you could, in theory, build a small slip roll to suit this job.
Different means of bending results in different amounts of spring back. If you have the work in a sheet metal brake and bend it past the yield point and keep bending it in a single shot, you'll get less spring-back than if you bend it in a bunch of smaller bends. Beating on it with a hammer is a bunch of small bends. You'll never get a 10mm part with a 10mm mandrel by hammering it.
You may get best results if you anneal the stainless to it's softest condition first. Since it's going to involve welding, you'll need to pickle it afterwards anyway.
Another thought is that you could make halves using a male die and using a hydraulic press, push the part into a urethane block, causing the shape to form. This will be a much closer fit, but you'll probably still have to make the mandrel undersize.
Another thought is that you could probably make this part out of steel or stainless steel on a lathe with a boring bar.
Another thought is that you could do this with metal spinning by starting with a tube on a steel mandrel, then swaging the tube into your cone shape with spinning tools.
Different means of bending results in different amounts of spring back. If you have the work in a sheet metal brake and bend it past the yield point and keep bending it in a single shot, you'll get less spring-back than if you bend it in a bunch of smaller bends. Beating on it with a hammer is a bunch of small bends. You'll never get a 10mm part with a 10mm mandrel by hammering it.
You may get best results if you anneal the stainless to it's softest condition first. Since it's going to involve welding, you'll need to pickle it afterwards anyway.
Another thought is that you could make halves using a male die and using a hydraulic press, push the part into a urethane block, causing the shape to form. This will be a much closer fit, but you'll probably still have to make the mandrel undersize.
Another thought is that you could probably make this part out of steel or stainless steel on a lathe with a boring bar.
Another thought is that you could do this with metal spinning by starting with a tube on a steel mandrel, then swaging the tube into your cone shape with spinning tools.