Wire EDM

K

kb58

Joined
Nov 24, 2025
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I'm a retired SW/HW engineer and greatly enjoy building things. After designing and building two cars from scratch ("Midlana" and "Kimini") I decided to get into knife making but first built a heat-treat oven and 2-x72" belt grinder. I made three kitchen knives, each a different style but all with a non-symmetric grind, in (what I consider now to be) a somewhat pointless goal of making them "non-stick. Anyway, after that, a defense knife for a relative in law enforcement, then looked for new projects. The latest project really pushed my abilities, but it's done, a wire EDM machine.
I have a (possibly bad) habit of building something for the sheer coolness of it, without giving much thought about how it'll be used. Such is the case here. Outside of purely industrial uses, I thought that maybe knife makers might benefit from EDM's abilities to cut intricate patterns into any type of metal. Personalized maker marks come to mind, or blade anchoring pins, but beyond that I'm not sure. I made the mistake of suggesting that it "could" cut patterns into blades, only to be met with derision and dismissal. I was a bit surprised, as "mmm, no thanks" would have been sufficient. Probably the best is to give you the particulars of the process and you tell me if there is any application:
1. Uses a 0.01" diameter wire to cut nearly any pattern in any metal.
2. EDM's strengths are that it can cut very small and intricate patterns in even the hardest metals.
3. It can do inside and outside cuts, though outside cuts are simpler, not requiring rethreaded the wire.
4. My particular machine has a working envelope of approximately 10" x 10" and can cut material up to about 4" thick.

As mentioned, maker marks and personalized blade anchoring pins come to mind, but beyond that I'm drawing a blank. Any suggestions?
 
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Thanks for the tips. I should have stated up front that I'm not a vendor or a business, so I'm hoping that this isn't seen as advertising and violating vendor rules. At this stage I'm just curious whether such a service would be useful for one-off applications (at this point I have no interest in production jobs).

Cutting raw stock is straightforward, depending upon size and required accuracy.

Interesting comment about cutting primary bevels... I thought about that myself. A part recently cut off a stainless workpiece had an impressive edge. Not "diamond lap" smooth, of course, but a good start in that direction. I have a piece of Magnecut but am reluctant (due to its cost) to try cutting the primary bevel just as a test. I do have another knife in mind, though so I'll probably try it then once its profile is known.

I'll educate myself on "canister Damascus", I hadn't heard of it before.

One other thing to be aware of: Wire EDM is non-contact and cuts cool, so it doesn't cause heat distortion, BUT, if the workpiece is cold-rolled, it may contain high stress. This means that even though the wire EDM process itself doesn't cause heat distortion, warping can still occur if it's not hot-rolled or annealed.
 
I think Kershaw did some composite edge blades where edge steel was cut like a jigsaw piece and brazed to a different steel for the rest of the blade.

The original PITS folder used wire EDM to cut the titanium back spring bars.

Like many processes, wire EDM can be used for a bunch of stuff, but makes sense for only some! If the result (bevels) can be ground in or milled in with sufficient accuracy, there is no point in wire EDM cutting them. There are things that only wire EDM can do, so those are the things to concentrate on. It’s wasted on regular fixed blade profiling, unless your tang looks like one of Nathan Carothers’, might be most useful for folder blades with hidden stop pins, flippers, jimping or odd shaped opening holes.
As said, mosaic canister Damascus.
 
Completely agree on its best applications. A bandsaw, mill, waterjet, and laser can do a great deal of things, and only very intricate operations (and very hard metals) are bested by EDM. Sure, it can cut metal just like anything else, but the overhead (filters, DI pellets, and wire) makes it a tool for very targeted applications.
 
Coincidentally, a thread I flagged months ago and forgotten about popped up regarding carbide grinder platens. Cutting these is a no brainer and they could be cut to custom sizes. One issue at the moment is that I don't have the ability to "drill" holes, though since the holes are near the edge, the holes could still be cut via a slot from the nearest edge. The other issue is cost containment. I'll have to look into sourcing it but suspect it'll be from overseas, vulnerable to arbitrary tariffs, but I digress.
 
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If I had one I'd use it to profile knife blanks.

It could easily eliminate all but the sharpened edge of a knife.

The hardest part I think would be determi.ing the best way to hold the work for the desired process to be completed with as little downtime between cutting cycles as possible.
 
tinfoil hat timmy said:
If I had one I'd use it to profile knife blanks.

It could easily eliminate all but the sharpened edge of a knife.

The hardest part I think would be determining the best way to hold the work for the desired process to be completed with as little downtime between cutting cycles as possible.
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Agree, that's what I plan to do, but it's whether other people are willing to have me provide the service. Shooting myself in the foot perhaps, but I suspect not, that they'll just continue using a band saw and grinder (especially since they already have them) instead of paying someone, then shipping off the material and pattern, and waiting.
 
Sounds like you're getting started in knife making much the same way I did: build the tools first, then worry about the knives. :D
I had built a 2x72 grinder and a heat treat oven (and a handful of other smaller tools) before I had ever made a single knife. I haven't built a wire edm yet, but I have built a CNC router from scratch.

I'm less curious about the applications of a wire edm machine for knifemaking, but more about how you built one...

Are you using a Rack Robo kit with a 3d printer, or did you go another route?
 
Drew Riley said:
Sounds like you're getting started in knife making much the same way I did: build the tools first, then worry about the knives. :D
I had built a 2x72 grinder and a heat treat oven (and a handful of other smaller tools) before I had ever made a single knife. I haven't built a wire edm yet, but I have built a CNC router from scratch.

I'm less curious about the applications of a wire edm machine for knifemaking, but more about how you built one...

Are you using a Rack Robo kit with a 3d printer, or did you go another route?
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The machine is based upon Mike Bax's design (baxedm.com). He manufactures and sells the high voltage pulse generator, and provides free CAD figures, though it's up to builders to isolate each part in the drawing, apply dimensions, and fabricate the parts. Took about 3 months to construct. It's two-axis and has roughly a 10x10" work envelope, but it's fine for anything I expect to be doing in a residential 2-car garage.

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kb58 said:
Agree, that's what I plan to do, but it's whether other people are willing to have me provide the service. Shooting myself in the foot perhaps, but I suspect not, that they'll just continue using a band saw and grinder (especially since they already have them) instead of paying someone, then shipping off the material and pattern, and waiting.
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I know that David Mary David Mary uses a water jet guy. He seems to be doing well.

Id offer your services as saving money and time on tooling?
 
kb58 said:
Agree, that's what I plan to do, but it's whether other people are willing to have me provide the service. Shooting myself in the foot perhaps, but I suspect not, that they'll just continue using a band saw and grinder (especially since they already have them) instead of paying someone, then shipping off the material and pattern, and waiting.
Click to expand...

I think it would be best for smaller, intricate, blades Needing accuracy. Such as folder parts.
 
That’s really cool.

Just curious, have you done any testing to check accuracy? Cut a circle and check diameter and roundness or something similar.
 
An idea is taking shape:
Offer custom tungsten carbide cutting services, with the first product likely being belt grinder platens. Sure, others offer this, but I can offer customization so that they fit any machine, The EDM machine will need the ability to "drill" holes though, both for screws and threading the wire for inside cuts. Until that's implemented, a work-around is to cut in from the sides to create any required holes. I'll be contacting manufacturers of tungsten carbide to see what 2" x 8" x 1/8" pieces run in quantity.

The above is a stream of consciousness and subject to change at any time. If the cost of raw material is too high, other ideas will be dreamt up. It does seem promising though, since it's a process on a material not easily handled by other means, and few shops have EDM machines. Also, offering custom work keeps competition at bay, since many companies only offer one-size solutions. It's probably also a small market, which I'm okay with because it means that it's not profitable to larger companies and lets me enjoy retirement.

Now, other than grinder platens, I'm unsure how much such a service would benefit the knife-making community. Tungsten carbide is incredibly hard but also brittle. A knife with this edge would be awesome - right up until it's tapped against something like a ceramic countertop, or worse, dropped. I understand that some knives made of straight tungsten are more resilient, so that might be something interesting to try (if not $$$$). There is also cutting already-hardened blanks of whatever material is this week's darling but as mentioned, I suspect most people will just keep using their band saws and grinders.
 
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I don't believe so. The cutting takes place submerged in water, so there is effectively no heating of the work piece. That said, microscopically, the metal will get hot immediately adjacent to the cutting wire, but it's so thin that whatever's left will be removed by subsequent grinding.
 
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