How do you grind kitchen knife blades (stock removal) ?

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Matus

Matus

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Hi,

as you may have noticed I started a thread with some questions about belt grinders. However I have realised that it would be very helpful to me to find out how do you guys grind your blades - in particular if you make your knives via stock removal method.

What I would like to ask is:
- how do you hold the blank?
- how do you setup your grinder?
- how do you get the profile you want (convex, wide bevel, etc)?
- how do you grind the distal taper?
- do you 'free hand grind' or do you use the tool-rest?
- do you use some jig to keep a give angle while grinding?


I am about to start stock removal on a little 1x30" grinder and would really appreciate you input so that I can avoid unnecessary mistakes.

Thanks in advance :)
 
YouTube has some in depth videos on the subject
Try Walter sorrels or Gough customs. They have great vids
 
I have seen most of those videos (and they are indeed great), but none of the guys grind complex convex and/or wide bevels on kitchen knives - they do mostly full flat grinds on outdoor knives. OK, Walter has one video where he makes one chef's knife, but seems to put a more-less flat grind without elaborating on the details.
 
Matus, You're asking for advise that takes years and thousands of knives to master. I've often thought about stock removal and making my own blades. Guess Marko's grinder got me excited. If I were starting from square one, I'd try to find a local school or local smith to teach you the ropes. A formal class would be ideal, you live in Germany, aren't you guys known for being the worlds best mechanical engineer, aerospace, automobiles... Got to be somebody associated with these place have experience with a grinder? Give them the ole puppy dog eyes and promise to be a good student.

or

You could just go to Goodwill (not sure what they call it in Germany) and pick up a box full of old crap knives and just go to town. As long as you've got the proper safety wear, you'll be ok, and will learn, but very slowly.

I'm sure you already have considered this, just saying...
 
Didn't Gandhi once say, "make knives, not excuses". I might be miss quoting the Mahatma. Just start!
 
Oh, I am not hesitating to start and to learn - it is very clear to me that there is no way around learning-by-doing here. I plan to use some cheaper steel I have, cut it to some rudimentary blade blanks and grind away until I can get some consistency. I am just hoping for a few tips & tricks as at the end - I want to be able to grind a bevel that works well - what means getting different angles at different positions (distance from the edge) and I could use some advice there.

I did briefly check out the possibility to take a class (and will look into that more seriously), but most what I found concentrates on forging (kinda get one forged blade in a course of one weekend - that does not sound to me much like learning the technique, but just satisfy the one-in-a-time curiosity). I would be interested in classes, but would first have to find a knife maker whose work I like AND who is actually interested in giving such a class.
 
If you find yourself going on elk safari up north you know where to find me :)

I'll say though that I believe in finding your own way, what works for you..

I free hand, and recently I've thought it's actually alot like working on stones, you put pressure where you want to remove steel, and find the motion needed to get to that spot without messing up another, or get to much heat.
 
Thanks Robin. That is the kind of advice I am looking for. Should I find the excuse to come up north again (we have been to Norway last year and only crossed south Sweden) than I will give you a call :)
 
Hi Matus,
To keep it simple try to think of the side of the blade in two large sections, there's the flat section that goes mid-height to spine and then there's the bevel which goes from mid-height down to the edge. These two sections are mostly ground independently with most time being spent on the bevel. Once you have the bevel ground and some taper ground into the upper flat/spine section you can either leave the transition line as is or blend it all together to form a more convex shape.

And before all that, make the profile of the blade perfect - this is VERY important to remember. You'll be kicking yourself in the ass if you work on the profile after grinding the sides of the blade.

That's the most basic of it.

Dave
 
You might want to scribe a center line in the edge to ensure even grinding along the length. This can be very helpful when starting out.

Also, stop and look as you go, inspect from all angles to make sure you're grinding even and no curves/warps or other weird things are happening.
 
Thank you Dave for your advice. That is very good point about the doing the profile first.
 
So, I have just received 11 pieces of 1.2442 in 3.3 x 60 x 660 mm, 2 pieces of 2.7 x 40 x 650 mm and 2 in 125SC 2.7 x 50 x 735 mm.

On top of that I have incoming O1 (1.2510) - 2 pieces in 2,2 x 40 x 1030mm and 2 in 3,2 x 60 x 103 0mm AND 1.2519 (O1 with more C and a lot more W) in 2,2 x 50 x 1000 mm.

That makes it all together nearly 15m of steel - I should be set for a while :) The 1.2442 is the last stock available in this size (from Achim in DE) - there is little more in smaller width available. I plan to use the one I bought for gyutos once I get some grinding experience. The O1 is form China (as I learned afterwards) and will be in the first place used to learn grinding.

I am very curios about the 125SC (further development of SC145) - with little less C and little more Mn (to improve HT properties) - should be similar to white#2 but even more pure (!). I am really curios about it. The nice thing is - there is plenty of this steel for years to come and it can be had in thickness suitable for stock removal kitchen knife making.

All the above probably sounds a little crazy, but I am really motivated and not I have all the basic tools (little grinder, angle grinder, etc.) to get the ball rolling. I am really curios how long it will take me to get the basic grip on the grinding (so that the result resembles a knife).

My current plan - make a batch of 150 or 180 mm WA petty blanks from the O1 steel and use them to learn the basic grinding. I will use our Yoshikane SLD 150 as a template for the profile and for the bevel geometry.
 
gic, the steel choice will in my (very limited) experience depend on whether you plan to heat treat your own blades (but probably do not have a proper HT kiln yet I suppose). If yes, than steels like 1075, 1084 or O1 are often recommended since these can be HT without strict temperature control. If you will outsource the HT (I do), than it will depend on what steels can given shop or company heat treat.

Even if you outsource your HT and are not really limited by the steel choice, I would still go with a simpler, low alloy carbon steel, since it will be somewhat easier to cut and grind than some other steels. For comparison - I found 80CrV2 or O1 easier to grind and cut as for example D2. This is in particular relevant if you plan to grind the blades with a file (or manual filing jig) and not with a belt grinder. Also - it does not make much sense to start with some expensive steel.

What may help is to to buy precision ground steel (in particular for kitchen knives) - this will eliminate the need to straighten the stock steel (which is normally cut to size from large sheets and gets slightly distorted in the process). This costs extra, but makes your life much easier - in particular if you do not have a dedicated tools to make the steel as flat as possible before you start cutting the blank out.

Check out youtube videos from guys like Nick Wheeler, Walter Sorrells, Caleb White Knives and others. None of these guys specialise in kitchen knives, but they have excellent videos on general stuff (tools, how to make basic knives, handles, mistakes to avoid, etc.) which I found (and still find) very helpful.
 
Just got my first hands-on experience. I was working on the 240mm D2 gyuto that I ground initially with a file (a jig). To get the final shape I have used the techinique I 'discovered' (for myself so to say) when I cross-draw a file along the blade with both hands, I would hold the file under slight angle and thus use just the edge of the file. While this proved to be a very fast technique, it leaves VERY deep scratches. I only realised how deep these are once I have tried to remove them with 60 grid sandpaper. To cut the time down (which would have been hours even though the knife was no HT-ed yet) I moved to the grinder with the A100 gator belt (whether that was the right choice is something I do not know, but I did not want to use some coarse grit belt that would cut too fast) and started to remove the file marks. It turned out, that to get them all out (I am not quite there yet) I had to remove so much material, that the knife lost about 3mm of the blade height (before I started I had the edge thickness of some 0.3mm which I wanted to keep for the HT).

So - I did not loose the knife yet, but it is a lesson learned. Should I ever be using this particular filing technique than I will have to stop some 0.3 - 0.5mm (thickness wise) from the intended blade thickness and move to 'normal' filing and sanding. I will see ho much of the blade will be left once I will be done with the scratch removal (I do not want to leave that to after HT) - I may need to shorten the knife to 210 mm to keep some reasonable proportions.

I have more bevel ginding ahead - the 8 blanks for 180mm petty knives were cut with a angle grinder yesterday and now wait to be grind to final profile and then beveled.
 
Haha it's not going to be long now before you go buy a 2x72.

Looking forward to see some pictures.
 
RDalman said:
Haha it's not going to be long now before you go buy a 2x72.

Looking forward to see some pictures.
Click to expand...

Indeed :) I already have one on radar already, but du not want to push for it too soon - I can learn a whole lot before getting a better (and more expensive) tool. I first need to prove (to myself at least) that I can make a knife that is worth using. I am not quite there yet ;)

I do take photos, if not for anything else then to entertain those more experienced makers :) It must be load of fun watching beginners to roll blindly towards inevitable mistakes :)
 
I would have one question - how do you guys hold the blade while grinding the bevels? Obviously one hand is holding the tang, but I am having hard time to figure out how do hold the blade to make sure that I keep the angle and constant pressure while moving along the belt - AND not grinding my fingers :)

And second question - do you grind on the platen in vertical or near horizontal position?

thanks :)
 
I like to think it's similar to working on a stone. The hand not holding tang is doing most of the control work, if that makes sense. In reality they probably help eachother. I use all the grips, and most imaginable positions, whatever works to get desired effect. I've never cared for angles much, I think of it more to remove steel wherever needed to get the blade I want. Usually it's about getting the right contact point/applying some pressure in the same sense you would when working on a stone. This may not relate at all to your tools and process though, since I'm grinding hardened steel which tends to "skate" the belt and not grab like soft steel does.
 
You know those Japanese knifemaker grinding videos where they use a plank with metal brackets, pins(?) and a tightening wedge on them to hold the knife when they are grinding on a waterwheel? Maybe you can make something like that too.

[video=youtube;iCtx8VYxUK4]https://www.youtube.com/watch?v=iCtx8VYxUK4[/video]

I think Dave Martell had modified his Harbor Freight 1X30 for horizontal operation. I'm assuming that's the preferred orientation when working with knives.
 
Thanks. That helps and timing is spot on - I have 8 180mm petty blanks ready for bevel grinding.

That video is really nice - masters tend to make what they do look so easy.
 
Hi: Good luck in you new endeavor. I took a class with Dave Lisch here in Seattle. He provided j shaped pieces of plastic, I think cut from a plastic cutting board, which we used to exert even pressure on the blade as we pulled it across the belt. We used a flat platen and a tool rest. You could use anything I think, such as a block of wood. This technique really helps in exerting even pressure and maintaining a constant angle as you pull the blade across the belt. It also keeps your fingers from burning, but you need to be aware of blade temp. Hope this helps.
 
This is a fairly decent and in-depth video on how to grind a chef knife.

Part 1
[video=youtube;hXeiFVSYdhc]https://www.youtube.com/watch?v=hXeiFVSYdhc[/video]

Part2
[video=youtube;XiVuuCMX0RA]https://www.youtube.com/watch?v=XiVuuCMX0RA[/video]
 
Thanks. I came across the first of the two videos recently and need to look at it more closely. But I would appreciate input from those more experienced on the technique showed in the videos.
 
Matus said:
Thanks. I came across the first of the two videos recently and need to look at it more closely. But I would appreciate input from those more experienced on the technique showed in the videos.
Click to expand...

I didn't watch all of it, but some thoughts. He scribes his slightly bent blank pushed down to be straight, so his scribed lines will flex back out of true as soon as he lets go of the pressure. His "finished" blade looks unsharpened and thick at the edge to me. It probably makes a good enough blade, but one can go at it from different perspectives. You set your own standards for what you want your knives to be, and then find a way that works for you, how to make it.

My tips for you knowing some of how you've previously done; Keep the atoma plate handy to check your progress, hog off steel with whatever tool and technique works best for you. Don't be afraid to mess up, but keep fixing your mistakes.
 
Thanks Robin. One thing that most (if not all) who actually make knives worth buying say the same thing - keep improving your work all the time. I completely agree. But at the very beginning there is also a danger of trying to 'polish a turd' (that is a quote). I.e. trying to get something much better than one at given stage is able to.

I have just started with the learning - my first 180mm petty blank is nearly finished - I am deciding on how thin (I mean further up from the edge, I will keep the edge at around 0.3 mm thick) should I grind the blade prior to HT. On one hand it will be harder to grind after HT, on the other hand I expect the hardened blank to have better 'feedback'. But that is why I prepared 8 of these - so that I can try things out and learn. It is so much fun :)
 
It's great to see the knife making bug getting to so many people. I enjoy these threads a lot.
 
Dave, it is the support and advice that you, experienced knife makers, share with us that makes it possible for us to to learn much faster. Big 'thanks' from my side for that.
 
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