A very common occurrence that we come across in the quoting area is the occasional part that should be cold headed (cold forged) instead of machined. If we recognize this, we usually let our customer know and let them decide if they want us to quote machining still. We bring this up because we know that historically, turning is not competitive with parts that should be cold headed so we don’t want to waste our time and our customer’s time.
Cold heading is competitive because it’s very fast and there is very little scrap. In cold heading, slugs of wire are cut and then pushed into a die that is in the shape of the part that needs to be made.
There are a few criteria that can help determine if a part needs to be cold headed or machined. Typically, in order to be competitive and get affordable material, cold heading companies require larger volumes of parts to be purchased than most machine shops. While some machine shops have capabilities of running high volume production (like R&H), most cold headers only run high volume production. Other limitations of cold heading are complex geometries and very tight tolerancing. Machining, specifically turning, excels at cross holes, internal diameter work, and other complex geometry. While machining can machine most of these complete, cold heading typically cannot so they either cannot make the part or secondary operations must be done. Machining also excels at very tight tolerancing. Cold heading can hold +/- .005”, though I’m sure there are some out there that can improve on that, however machining can hold tolerances closer to +/- .0001” or so.
If you still are unsure, we would always be happy to take a look at any parts that need to be manufactured and we will let you know if we can quote them or not. I hope this helps at least a little bit when it comes to determining machining vs. cold heading.