[throwaway81523]

Cool, thanks, yeah for a single hole, doing it by hand with a needle file sounds more practical. Does something like this seem CNC-able?

https://sakparts.com/products/can-opener-diy-tool-part-for-8...

The idea isn't to duplicate an existing can opener, but rather to make custom specialized tools to fit into a SAK, or replacement knife blades out of specialty knife steels (i.e. very hard, so probably difficult to machine). It wouldn't just be for SAK's but also for other folding knives, each with its own special cutting pattern to work with its pivot and locking system.

Titanium is another material of interest, for ultralight gear.

All of this is probably impractical at the hobbyist level with limited work space, though. Oh well.

[Animats]

DIY knife forging is common. Search "knife forging". Look around for classes and forges with training. There's a huge amount of info on knife making and metallurgy. People obsess on this stuff. A good knife is a trick of metallurgy. The blade must be hard at the edge to be sharp but ductile in the body so as not to be brittle. How to do this is well understood today, but there was much mystery around it for centuries. If you're fascinated by metalworking, but don't have to make machine parts, that's a hobby direction.

Victorinox knife manufacture.[1] Stamp, heat treat, grind, polish. They're not exotic blades, just good manufactured stainless steel parts.

A primer on machining titanium.[2]

[1] https://www.popularmechanics.com/adventure/outdoor-gear/a351...

[2] https://www.harveyperformance.com/in-the-loupe/titanium-mach...

[throwaway81523]

Sure, knife forging is one thing, but the idea of making replacement blades for folding knives sounds like it takes machining, because of the weird shapes needed at the pivot end, especially for weird locking mechanisms. It would be nice to be able to do that at a semi-commercial level if one were to get into it at all. Victorinox is on a completely different scale, making millions of units of whatever. But forging is for making one or two of something, while CNC machining is interesting for making a few hundred.

In practice I don't have it in me to pursue something like that for real. It's just interesting to find out about.

If I simply wanted to make knives, then no machining would be needed, just some cutting discs and belt sanders. It's the specific thought of making replacement blades for existing folders that seems to want more automation. I guess there are existing shops that can do that type of thing from a CAD drawing though.

[WillAdams]

We (ob. discl., I work for Carbide 3D) have a video series on doing this:

https://www.youtube.com/watch?v=G5TYla5x-Nk

[throwaway81523]

Thanks! That looks like just what I want. I looked at the first few seconds just now, and will watch the whole thing later.

[bluGill]

Knifes are done with heat treating. you need to get the steel red hot and follow the proper cooling process. You machine soft iron to close then make it too hard to machine, finally grindit to the perfect size.