I have a very specific hole type I have to make in 304SS and I'd like some knowledgeable advice before I even start.
The 304 is 1/2" thick. I need a through hole 1.66" diameter, and a counter bore 1.875" diameter by 1/4" deep. There are no geometry obstructions, so I can use a very short tool. I have up to 4000rpm available, with lots of torque, and the spindle is very rigid. This has to be done with ONE tool, which will surely be an end mill. Should I do the through hole with a helical path, and then the same for the counter bore, both from the top down? Or should I do a smaller helical bore and then do concentric arcs to work my way out to the finished diameter for both features more like a high speed machining approach? Based on your suggested method, what diameter end mill should I use? 0.030" radius is tolerable for longer tool life. My goals are reliable process, good tool life, and good surface finish. This is low production, so I don't mind spending more on the right tool if I can get confident direction up front. Ask questions if required.
The 304 is 1/2" thick. I need a through hole 1.66" diameter, and a counter bore 1.875" diameter by 1/4" deep. There are no geometry obstructions, so I can use a very short tool. I have up to 4000rpm available, with lots of torque, and the spindle is very rigid. This has to be done with ONE tool, which will surely be an end mill. Should I do the through hole with a helical path, and then the same for the counter bore, both from the top down? Or should I do a smaller helical bore and then do concentric arcs to work my way out to the finished diameter for both features more like a high speed machining approach? Based on your suggested method, what diameter end mill should I use? 0.030" radius is tolerable for longer tool life. My goals are reliable process, good tool life, and good surface finish. This is low production, so I don't mind spending more on the right tool if I can get confident direction up front. Ask questions if required.