Thank you for providing such information.
Yeah, I also thought about them stealing the design, but, I don't see any other opportunity for me as a beginner. I can't even imagine that a company like Spyderco or Benchmade, or at least CRKT would take my design. I have no idea of how to work with autoCAD, I mean, I'm a student.
Actually, I'm now having time of deciding what major to take in college. Maybe I should take some sort of engineering or something where they teach working with all that graphic stuff.
What kind of knife did you have in mind? There is a dramatic difference between a fixed blade and a folder. A bad fixed blade design can still be a functional knife, but a folder, while not a complex machine, is an assembly of interconnected and interdependent parts that must be carefully fitted to close tolerances. We have only to look at Bark River, a very experienced knife making company, and the widely erratic quality of their first folding knife attempt that has been iterating for several years and still isn't released. A fixed blade can be made from a draft paper sketch, a folder will take iterative engineering work, drafting, sketching, CAD/CAM, modeling that could range from clay and wood to 3D-printed prototypes, etc.
To make just one knife is no big deal, especially if it is a fixed blade, but it won't be a company that does it, you'll need to go to a knifemaker who is willing to try making your design. The knifemaker will know more than you, so he or she may tell you that your design is impractical or not feasible or just not a great knife design. You may also have to reach out to several people, because knifemakers also have a sense of their own skill and artistic interest, so any given knifemaker may think that what you are asking for is outside her skill range or outside his sense of artistic design and therefore decline to make it. Well-known knifemakers are highly unlikely to take your work because why would they, they all have years-long waiting lists for work as it is, and a much lower willingness to compromise on their own design and materials aesthetic. Cost for this could be from $300-$1,500 depending on what kind of knife you are making and what materials there are. Also the odds of someone being willing to make a custom
folder to your specs I think are very low, because the odds of you having a functional folder design are also very low, so anyone with the skill to make a folder will also know that in taking on your project they are committing to a black hole of time commitment that is not going to be worth the aggravation.
To make even a small batch of machined knives is going to be thousands of dollars.
Mechforce has done some very good OEM manufacturing in fixed and folding knives and has the capacity to do batches as small as ten pieces. However, economy of scale applies. The fixed costs for engineering and machine tool fixturing and setup do not change if you are doing ten pieces or ten thousand, only the variable costs in raw material and MRO inventory scale. No idea what Mechforce would charge. I myself have been tempted to design a small fixed blade out of frustration with the inability to find a small, pointy, lightweight wharncliffe defensive knife for running and see if Mechforce would make me a small batch. But I suspect it'd be in the thousands of dollars range, plus they are a general machine shop that does a lot of knives but doesn't specialize in them, so I don't think they heat treat in house, and you'd have to have blades sent to Peters or someone for heat treat as well, and possibly for coating if Mechforce can't do the coating you want (I don't think they can do DLC, for example).
If you get serious about this, you'd be much better off approaching a machine shop with small-batch experience with knives than a large company. I doubt Civivi would even answer your e-mail, and WE or Reate wouldn't set up to do a run for you without a commitment to 500+ pieces that you would be on the hook for buying and then selling yourself.
This famous saga from an ignorant (I do not mean this as a slight, I just mean it in terms of "Member has a design for a knife he really wants made but has no design or knifemaking experience") member can be instructive. He eventually got someone to make something, and he was happy with it. Good for him! A lot of other makers are like "That's still a bad idea," but, hey, a great guy did him a favor, and it turned out to his satisfaction.