Advice on first knife making idea.

[scott kozub]

There's all kinds of jigs but the vast majority are simply a block of wood cut to an angle or two plates with an adjustment that the blade get clamped to and they rest on a table. Just look at YouTube. Very easy to use and make. If you have a tilting table then a square tube or angle iron will suffice. The thing I don't like about them is that you have to reposition the knife to grind the other side. I also like to have my fingers right on the blade at the belt so I can monitor the heat. Below is a jig I made when just starting out. It makes it really easy dunk the blade and adjust the blade when grinding to the tip. Also very easy to adjust on the fly without tools.

 

[Loren Jones]

There's all kinds of jigs but the vast majority are simply a block of wood cut to an angle or two plates with an adjustment that the blade get clamped to and they rest on a table. Just look at YouTube. Very easy to use and make. If you have a tilting table then a square tube or angle iron will suffice. The thing I don't like about them is that you have to reposition the knife to grind the other side. I also like to have my fingers right on the blade at the belt so I can monitor the heat. Below is a jig I made when just starting out. It makes it really easy dunk the blade and adjust the blade when grinding to the tip. Also very easy to adjust on the fly without tools.

thanks for the great video. That’s a really cool jig.

 

[Hengelo_77]

I made my first knife with hand tools only out of RWL34 (cpm154)
It is a good stainless steel and well workable

 

[Loren Jones]

I made my first knife with hand tools only out of RWL34 (cpm154)
It is a good stainless steel and well workable

Good to know someone else started with a somewhat higher alloy steel on their first knife.

 

[Willie71]

Ok, so I took the plunge. I ordered a Palmgren 2x42 belt grinder and a12”x4”x.1” piece of CPM M4. I know I should’ve tried something easier but I’ve made my choice. I do plan to practice some grinding with some
Mild steel from the hardware store and I may do a full practice version of my knife from 1/8” mild steel. I went ahead with M4 because it seems like a great kitchen knife steel to me and I figured I’d just start learning to work with it on simple designs and then work up to more difficult designs as I develop skill and knowledge.

I plan to use a jig to assist me with the grinding. Are there any plans out there for blade grinding jigs, or is that a bad idea.

I was going to order standard abrasives from klingspor for pre heat treat grinding. Should I order something special for the final grinding of the edge and for finishing after heat treatment?

it will be awhile before I’m able to start but I’ll put up a thread here asking lots of advice.
Thanks for the info and encouragement so far.

This is not meant with malice, so please take it as friendly advice. You asked us for advice on steel selection, and we provided you with sound advice. You chose to ignore that, but are now asking for more advice. I am personally less inclined to take my time to type out responses if they are likely to get ignored.

The reasoning behind suggesting simpler steels isn’t just about ease of working, even though that is the main reason. Secondly, it is quite possible your first two or three knives won’t even get finished, due to mistakes along the way. With higher priced steels this is a harder pill to swallow. Harder to work steel makes it more likely to make mistakes.

I have friends and customers who have knives I made from 15n20 and 8670 that are more used than knives with more exotic steels, even some of my earlier knives. The main advantage of the supersteels is the ability to push the geometry to extremes when heat treated properly. The wear resistance isn’t a real advantage with lousy geometry. There is little point in using a super steel and not grinding to 0.005” or less before sharpening. You can get that geometry with 15n20, 8670, and AEB-l, at much lower cost. You are also less likely to burn the steel grinding low alloy steels.

I cringe when people spend hundreds on materials like damascus, mammoth ivory, 5a Koa etc. and make a prison shank. Save those materials until you have properly functioning tools that are esthetically pleasing. It easily takes 30-100 knives to find your style and refine geometry. It takes way more knives than I have made to be an expert at this.

Anyway, just my $0.02.

 

[Loren Jones]

Willie,
No offense taken and I totally understand what you mean when you say you may be less likely to offer advice further if I ignored previous advice. That makes complete sense.

I thank you for taking the time in this reply to explain your thoughts on why more basic materials make sense to start with.

I do hope to have this knife very thin behind the edge before sharpening so I understand what you say about the better steel being a waste if you don’t take advantage of it. It’s because I want a knife that can hold up at that kind of geometry. Obviously it’s clearly true that I will have a hard time attaining that geometry. Good point for sure.

On the other hand, my piece of CPM M4 is only $48 and a piece of AEBL the same size may be $25 or so. For $23 I’m willing to give it a try. I’m also hoping that my choice of a simple profile on my first blade will help improve my chances of success.

I will check carefully with my heat treat company about how thin I can take it before heat treating then it’s the finish grinding to get down to that narrow profile behind the edge that seems to me like it will be the trickiest part.

Thanks again and sorry if my disregard for advice offered here has offended.

Thanks for your time so far.

This is not meant with malice, so please take it as friendly advice. You asked us for advice on steel selection, and we provided you with sound advice. You chose to ignore that, but are now asking for more advice. I am personally less inclined to take my time to type out responses if they are likely to get ignored.

The reasoning behind suggesting simpler steels isn’t just about ease of working, even though that is the main reason. Secondly, it is quite possible your first two or three knives won’t even get finished, due to mistakes along the way. With higher priced steels this is a harder pill to swallow. Harder to work steel makes it more likely to make mistakes.

I have friends and customers who have knives I made from 15n20 and 8670 that are more used than knives with more exotic steels, even some of my earlier knives. The main advantage of the supersteels is the ability to push the geometry to extremes when heat treated properly. The wear resistance isn’t a real advantage with lousy geometry. There is little point in using a super steel and not grinding to 0.005” or less before sharpening. You can get that geometry with 15n20, 8670, and AEB-l, at much lower cost. You are also less likely to burn the steel grinding low alloy steels.

I cringe when people spend hundreds on materials like damascus, mammoth ivory, 5a Koa etc. and make a prison shank. Save those materials until you have properly functioning tools that are esthetically pleasing. It easily takes 30-100 knives to find your style and refine geometry. It takes way more knives than I have made to be an expert at this.

Anyway, just my $0.02.

 

[Loren Jones]

double post

 

[Storm W]

Willie,
No offense taken and I totally understand what you mean when you say you may be less likely to offer advice further if I ignored previous advice. That makes complete sense.

I thank you for taking the time in this reply to explain your thoughts on why more basic materials make sense to start with.

I do hope to have this knife very thin behind the edge before sharpening so I understand what you say about the better steel being a waste if you don’t take advantage of it. It’s because I want a knife that can hold up at that kind of geometry. Obviously it’s clearly true that I will have a hard time attaining that geometry. Good point for sure.

On the other hand, my piece of CPM M4 is only $48 and a piece of AEBL the same size may be $25 or so. For $23 I’m willing to give it a try. I’m also hoping that my choice of a simple profile on my first blade will help improve my chances of success.

I will check carefully with my heat treat company about how thin I can take it before heat treating then it’s the finish grinding to get down to that narrow profile behind the edge that seems to me like it will be the trickiest part.

Thanks again and sorry if my disregard for advice offered here has offended.

Thanks for your time so far.

Your problem is going to be that you don't have the equipment to get it really thin behind the edge with CPM M4. The one thing that you can do is use a diamond stone to thin the final edge. You can only go so thin before you heat treat without causing problems. For kitchen use the biggest performance gain that you can get is getting the thickness behind the edge to be under five thousandths and the best use of using fancy steel is to be able to support that thin geometry. If you used AEB-L or even S35VN you could have gone around ten thousandths before heat treatment and used sandpaper to convex and thin the final edge. The vanadium carbides in CPM M4 are harder than the aluminum oxide grit on regular sandpaper and I think it would be pretty impossible to try using a ceramic belt by hand to thin your edges. You can use a diamond stone but that isn't the cheapest thing to use. If it were me with your current setup I would get some AEB-L or S35VN and make your kitchen knives out of that and save your CPM M4 to make a sporting type of knife out of where ten thousandths is still a reasonably fine edge thickness.

 

[Loren Jones]

Storm W,

Thanks for taking time to reply. Using a diamond stone to get down to a narrow behind the edge geometry after heat treat and before actually sharpening is something that had been on my mind the last 24 hours after thinking about Willie's post. I was thinking that would be the only method I would have available to come down from whatever minimum thickness my heat treater (planning to use Peters) recommends to that 5 thousandths range. So I'm really glad to hear you suggest that. I've been wanting to try a diamond stone anyway so I don't mind picking one up to go with my Chosera stones.

I see your point about using the M4 in a sporting knife, but I don't use knives of that type in an outdoor setting as much as I would like. I could try one in AEBL first and save the M4 and I hear the wisdom of those recommendations but I'm just not sure I'm going to find a ton of time to invest in building multiple knifes as a major hobby. I just know how many projects I have around the house that I hope to never get to but never do, so I'm not counting on making multiple knives a year or whatever. So I'm going to stick with the M4 for this Chinese vegetable cleaver effort and if I ruin it I guess I'll be out a $48 piece of steel and some time. The belt sander/grinder I ordered will still be useful even if I never make another knife.

I do greatly appreciate the diamond stone advice. Do you have a particular diamond stone that you like best?

Thanks again,
Loren

Your problem is going to be that you don't have the equipment to get it really thin behind the edge with CPM M4. The one thing that you can do is use a diamond stone to thin the final edge. You can only go so thin before you heat treat without causing problems. For kitchen use the biggest performance gain that you can get is getting the thickness behind the edge to be under five thousandths and the best use of using fancy steel is to be able to support that thin geometry. If you used AEB-L or even S35VN you could have gone around ten thousandths before heat treatment and used sandpaper to convex and thin the final edge. The vanadium carbides in CPM M4 are harder than the aluminum oxide grit on regular sandpaper and I think it would be pretty impossible to try using a ceramic belt by hand to thin your edges. You can use a diamond stone but that isn't the cheapest thing to use. If it were me with your current setup I would get some AEB-L or S35VN and make your kitchen knives out of that and save your CPM M4 to make a sporting type of knife out of where ten thousandths is still a reasonably fine edge thickness.

 

[scott kozub]

I recently bought an atoma 400 that I like a lot. There's also shapton glass and DMT that are all good. The good thing with diamond stones is that they stay flat and you can use them for flatening your other stones as well.

Storm W,

Thanks for taking time to reply. Using a diamond stone to get down to a narrow behind the edge geometry after heat treat and before actually sharpening is something that had been on my mind the last 24 hours after thinking about Willie's post. I was thinking that would be the only method I would have available to come down from whatever minimum thickness my heat treater (planning to use Peters) recommends to that 5 thousandths range. So I'm really glad to hear you suggest that. I've been wanting to try a diamond stone anyway so I don't mind picking one up to go with my Chosera stones.

I see your point about using the M4 in a sporting knife, but I don't use knives of that type in an outdoor setting as much as I would like. I could try one in AEBL first and save the M4 and I hear the wisdom of those recommendations but I'm just not sure I'm going to find a ton of time to invest in building multiple knifes as a major hobby. I just know how many projects I have around the house that I hope to never get to but never do, so I'm not counting on making multiple knives a year or whatever. So I'm going to stick with the M4 for this Chinese vegetable cleaver effort and if I ruin it I guess I'll be out a $48 piece of steel and some time. The belt sander/grinder I ordered will still be useful even if I never make another knife.

I do greatly appreciate the diamond stone advice. Do you have a particular diamond stone that you like best?

Thanks again,
Loren

 

[Loren Jones]

Thanks Scott, I have been thinking Atoma may be the way to go. How aggressive do you find that 400? I do already have a flattening stone to use on my Chosera 800 and 3000 so I’m really just looking at a diamond for helping final thinning behind the edge on this M4 after it’s hardened and for repair of major damage or reproducing. Is your 400 pretty aggressive?

I recently bought an atoma 400 that I like a lot. There's also shapton glass and DMT that are all good. The good thing with diamond stones is that they stay flat and you can use them for flatening your other stones as well.

 

[Storm W]

Storm W,

Thanks for taking time to reply. Using a diamond stone to get down to a narrow behind the edge geometry after heat treat and before actually sharpening is something that had been on my mind the last 24 hours after thinking about Willie's post. I was thinking that would be the only method I would have available to come down from whatever minimum thickness my heat treater (planning to use Peters) recommends to that 5 thousandths range. So I'm really glad to hear you suggest that. I've been wanting to try a diamond stone anyway so I don't mind picking one up to go with my Chosera stones.

I see your point about using the M4 in a sporting knife, but I don't use knives of that type in an outdoor setting as much as I would like. I could try one in AEBL first and save the M4 and I hear the wisdom of those recommendations but I'm just not sure I'm going to find a ton of time to invest in building multiple knifes as a major hobby. I just know how many projects I have around the house that I hope to never get to but never do, so I'm not counting on making multiple knives a year or whatever. So I'm going to stick with the M4 for this Chinese vegetable cleaver effort and if I ruin it I guess I'll be out a $48 piece of steel and some time. The belt sander/grinder I ordered will still be useful even if I never make another knife.

I do greatly appreciate the diamond stone advice. Do you have a particular diamond stone that you like best?

Thanks again,
Loren

My main stones are DMT bench stones. You can get double sided ones for around $60 on Amazon. M4 is my favorite steel so I don't want to make you think it's a bad choice. I just want you to realize that you have limited options. I hear that Peters is backed up because of the virus so you might want to look at having @JTknives do it for you. Ask him how thin you can go. Be careful about how much pressure you use when shaping it. The stuff I have used at least will suddenly link. It's not like it just gets a little curve it will suddenly let go and you pretty much have to scrap that part. Take it slow and finish like a final blade before you send it out. When you use the diamond stone just use light pressure and let the stone cut. To much pressure will strip some of the diamonds off. You also want to apply pressure so you remove steel towards the edge and not just thinning the entire blade. I found this out when trying to thin a M4 blade on a benchmade contego long before I got my grinder. I would get a course/ extra course stone. I use that as my main sharpening stone now. I'm not sure if you have tried course sharpening technique. I bring up a burr and then strop on a paint stir stick loaded with diamond paste. You should have a aggressive edge that will easily shave. I hope your project works out well. You certainly are jumping into the deep end but it can be done.

 

[Loren Jones]

Storm, thanks for the great reply.

When you say suddenly link, did you mean suddenly kink?

I was planning to have it fully formed except for the final thinning behind the edge before sending it out as you emphasized.

I have gone away a little bit for. The full flat grind idea to a somewhat graduated grind in perhaps three or four increments to give a slight convex so things won’t stick to it as much with that wide blade. That’s the way the cheap cleaver I have now is ground. So I was thinking to make a simple jig with angle iron and a couple thumb screws on the back edge to be able to adjust the angle and have that help me try to do the graduates grind. I know it is far from foolproof but am hoping it would help me accomplish an even graduated grind.

I was also thinking to make something akin to a file jig for whatever diamond plate I get to match the angle of my steepest grind before the edge to thin it out to that 5-10 thousandths range before sharpening. I plan to go very slowly with very light pressure and plan to use slightly less aggressive grit belts to help me not go too fast. I am nervous because the grinder I bought runs pretty fast.

how thin do you take M4 behind the edge for a kitchen knife?

Thanks for the tip on the heat treater. I will check them out. Whoever does it I’ll ask them how thin I can go.

So you sharpen on your coarse diamond then strip on balsa with diamond spray/paste. What size diamonds do you like in your paste? I’d like to try that. Do you find you can sharpen M4 on a whetstone like a chosera or similar?

My main stones are DMT bench stones. You can get double sided ones for around $60 on Amazon. M4 is my favorite steel so I don't want to make you think it's a bad choice. I just want you to realize that you have limited options. I hear that Peters is backed up because of the virus so you might want to look at having @JTknives do it for you. Ask him how thin you can go. Be careful about how much pressure you use when shaping it. The stuff I have used at least will suddenly link. It's not like it just gets a little curve it will suddenly let go and you pretty much have to scrap that part. Take it slow and finish like a final blade before you send it out. When you use the diamond stone just use light pressure and let the stone cut. To much pressure will strip some of the diamonds off. You also want to apply pressure so you remove steel towards the edge and not just thinning the entire blade. I found this out when trying to thin a M4 blade on a benchmade contego long before I got my grinder. I would get a course/ extra course stone. I use that as my main sharpening stone now. I'm not sure if you have tried course sharpening technique. I bring up a burr and then strop on a paint stir stick loaded with diamond paste. You should have a aggressive edge that will easily shave. I hope your project works out well. You certainly are jumping into the deep end but it can be done.

 

[Storm W]

Maybe the easiest thing to do is

Storm, thanks for the great reply.

When you say suddenly link, did you mean suddenly kink?

I was planning to have it fully formed except for the final thinning behind the edge before sending it out as you emphasized.

I have gone away a little bit for. The full flat grind idea to a somewhat graduated grind in perhaps three or four increments to give a slight convex so things won’t stick to it as much with that wide blade. That’s the way the cheap cleaver I have now is ground. So I was thinking to make a simple jig with angle iron and a couple thumb screws on the back edge to be able to adjust the angle and have that help me try to do the graduates grind. I know it is far from foolproof but am hoping it would help me accomplish an even graduated grind.

I was also thinking to make something akin to a file jig for whatever diamond plate I get to match the angle of my steepest grind before the edge to thin it out to that 5-10 thousandths range before sharpening. I plan to go very slowly with very light pressure and plan to use slightly less aggressive grit belts to help me not go too fast. I am nervous because the grinder I bought runs pretty fast.

how thin do you take M4 behind the edge for a kitchen knife?

Thanks for the tip on the heat treater. I will check them out. Whoever does it I’ll ask them how thin I can go.

So you sharpen on your coarse diamond then strip on balsa with diamond spray/paste. What size diamonds do you like in your paste? I’d like to try that. Do you find you can sharpen M4 on a whetstone like a chosera or similar?

Maybe the easiest thing to do is just talk about it. My number is 360.305 6225. Just shoot me a text and we can set up a time to talk about your project.

 

[scott kozub]

My atoma is a 400 grit. I bought it for setting the initial bevels. As I grind my AEBL to 0.002 before sharpening it only takes a couple light passes to raise a burr. I just used the atoma to clean up the grind on a scandi I just made in AEBL 62 HRC. It was taking a while so I moved to my 240 grit coarse stone which was faster. That was a bevel only 0.3" wide in AEBL which is way easier than the task you've set out on.

The atomas cut really aggressive when new but do break in.

If your trying to flatten an m4 ffg or high grind Chinese clever you have a lot of work ahead of you. Especially since it's your first knife and it going to be full of deep gouges and divots. One thing you'll learn is that's it takes practice to get a good finish off the grinder. Approach the belt at the wrong angle an you get a deep divot. That's where VFDs help a lot. You want it as clean as possible to reduce the handsanding. However, the more time you spend on the grinder the more you risk blowing out your temper. Make sure you check the edge with a brass rod before wasting too much time cleaning a soft blade.

You may also want to pick some rynowet redline sanding sheets in various grits. Don't even attempt this with hardware store sand paper.

 

[Loren Jones]

That’s super kind of you to offer. I’ll text you.

Maybe the easiest thing to do is

Maybe the easiest thing to do is just talk about it. My number is 360.305 6225. Just shoot me a text and we can set up a time to talk about your project.

 

[Loren Jones]

Thanks Scott. I appreciate the tip on the paper and the feedback on the Atoma. I’ll definitely check out that paper.

I don’t think I’ll end up doing a full flat grind, I may do 3 angles or 4 so there’s a slight convex in the first inch or inch and a half to promote better food release.

My atoma is a 400 grit. I bought it for setting the initial bevels. As I grind my AEBL to 0.002 before sharpening it only takes a couple light passes to raise a burr. I just used the atoma to clean up the grind on a scandi I just made in AEBL 62 HRC. It was taking a while so I moved to my 240 grit coarse stone which was faster. That was a bevel only 0.3" wide in AEBL which is way easier than the task you've set out on.

The atomas cut really aggressive when new but do break in.

If your trying to flatten an m4 ffg or high grind Chinese clever you have a lot of work ahead of you. Especially since it's your first knife and it going to be full of deep gouges and divots. One thing you'll learn is that's it takes practice to get a good finish off the grinder. Approach the belt at the wrong angle an you get a deep divot. That's where VFDs help a lot. You want it as clean as possible to reduce the handsanding. However, the more time you spend on the grinder the more you risk blowing out your temper. Make sure you check the edge with a brass rod before wasting too much time cleaning a soft blade.

You may also want to pick some rynowet redline sanding sheets in various grits. Don't even attempt this with hardware store sand paper.

 

[scott kozub]

Usually knives are flat ground to about 0.010 and then the final edge is convexed to less than 0.005. You'll still need to clean up the flats above the secondary edge. I didn't look at your grinder. Does it have a spot where you can slack grind? Slack grinding produces way less heat so less chance of burning your edge. Put your fingers on the blade right behind the belt as close to the edge as possible. If you worried about burning your finger tips your doing it wrong and potentially destroying your temper.

Thanks Scott. I appreciate the tip on the paper and the feedback on the Atoma. I’ll definitely check out that paper.

I don’t think I’ll end up doing a full flat grind, I may do 3 angles or 4 so there’s a slight convex in the first inch or inch and a half to promote better food release.

 

[Storm W]

You don't have to worry about burning the blade to much when you are doing before hardening. I don't think your little grinder is going to do a lot after its already hard but you aren't going going to have to remove all that much material so doing it by hand should be doable. Also at this point the carbides are going to be harder than the sandpaper so diamonds are going to be your friend. I get such good easy results from my course diamond sharpening that I don't think its worth trying to go finer. A lot of test show that the course edge last a lot longer as well. My personal theory about why this is is that more sharpening adds fatigue to the edge and let's it degrade faster. Using stones that don't cut the carbides will sharpen the knives but its likely that they at least partially do this by cutting the steel around the carbides and this isn't the best thing for edge retention. I did a conventional M2 full flat grind chef that should have came in at around 66Rc and it wasn't chippy for kitchen use. I think that's where I would start with your M4. I would try to get it down to around two to three thousandths before sharpening.

 

[Loren Jones]

Good info on grinding technique. So you are talking about a long flat grind and then a very short grind a couple degrees steeper to get from 10 thousandths to 5 thousandths. I guess that makes sense.

I ordered the palmgren 2x42 grinder. It runs fast so I wasn’t planning to put the knife on the grinder after it gets back from heat treat. That no grinder after heat treat approach may be more difficult if I do a full flat as opposed to having the first 1/2” or 1” be at a bit steeper angle giving me a smaller area to thin with the diamond plate.

Usually knives are flat ground to about 0.010 and then the final edge is convexed to less than 0.005. You'll still need to clean up the flats above the secondary edge. I didn't look at your grinder. Does it have a spot where you can slack grind? Slack grinding produces way less heat so less chance of burning your edge. Put your fingers on the blade right behind the belt as close to the edge as possible. If you worried about burning your finger tips your doing it wrong and potentially destroying your temper.