Good handle length for 8" chefs knife, integral bolster without forging or welding, and good behind edge thickness

J

JS knives and sharpening

Joined
Jul 21, 2024
Messages
8
Knife design

Hi there, I am new to knife making and just barely drew up my first design for an 8" chefs knife. The cutting edge length is 8" currently, while the handle is 4.3". Also, what would be a good way to get the bolster on there? I was going to have it be an integral bolster and be steel, but I do not have forging or welding equipment. I do have access to vertical mills, lathes, drill press as well as a belt sander and an anvil. I was thinking of pinning it but I am not entirely sure if that would be the best? Handle material will made of Ultrex Suretouch scales on a full tang. Other rods besides Mosiac pin will use Silver nickel rods from Jantz knife supply.


On to the next question, what would be a good behind edge thickness for it? The knife will be 2" tall at the heel and will be made from 2.5 mm stock. It will be made with 14c28n that I am going to be getting heat treated by Jarrod Todd to 60-61 HRC with the premier treatment package which includes
cryo. I was planning to have it have a full flat grind with a health amount of distal taper. I have ground other kitchen knives to .020" which seems to have worked well. I am trying to maximise performance while having enough steel behind the edge to be good for bulk food prep using good technique and still going through denser veggies with ease. Is there a better HRC for this use?

Do you have any critiques for the design that would help improve it?

Knife design is in link at top.

Thanks for the help!

Sincerely,
JS
 
Thanks! I will try to shoot for that! I do convex grinds too which helps and I am able to get them to cutting paper towels cleanly sharp. Just to be clear the .020" is at the end of the primary bevels, and I sharpen usually at 14° - 15°. Also, what are your thoughts on the knife design? It is that blue link at the top.
 
Last edited:
This may be a personal preference, but I think the edge is too flat. It's basically straight for more than half the length of the blade. That means that a rocking cut will come to a sudden stop very quickly. I find that uncomfortable and also impractical - there is much higher chance that the cut will not go through the whole piece all the way. When the edge is curved more, then only a small portion of it is in contact with the cutting board at all times, making it much easier to cut all the way through the whole length of the edge. Not sure if that makes sense the way I'm trying to explain. But my advice would be to make the edge curve more, and only make a small portion at the heel straight.
 
pafka said:
This may be a personal preference, but I think the edge is too flat. It's basically straight for more than half the length of the blade. That means that a rocking cut will come to a sudden stop very quickly. I find that uncomfortable and also impractical - there is much higher chance that the cut will not go through the whole piece all the way. When the edge is curved more, then only a small portion of it is in contact with the cutting board at all times, making it much easier to cut all the way through the whole length of the edge. Not sure if that makes sense the way I'm trying to explain. But my advice would be to make the edge curve more, and only make a small portion at the heel straight.
Click to expand...
Yep, I was just about to suggest leaving even just a very slight curvature along the belly.
 
Thanks so much! I was doing a profile that is more similar to what is on a Dexter, Mundials, and that is also on a bunch of other commercial kitchen knives. I personally have found in doing stuff in the kitchen I work at that having that sort of profile makes for good chopping, push cutting, and a decent rocker. On further examination of my other kitchen knives I use that I have found to work well, they do have that slight curvature even though to the eye they are almost flat. Thanks for pointing that out! Are there any other things that you might change to increase functionality?

Is it possible to get 14c28n to 63-64 HRC? How would one go about that? Do you know any third party heat treating services or people that might be able to do that and do a good job?

Here is the link to the ever so slightly modified design. It is hard to tell but there is curvature along almost that entire edge, the top one is the improved version:

Improved knife design

Sincerely,
JS
 
Last edited:
Jarod Todd will go higher than 60......that should be no problem for him.

The slight curve allows easier slicing, so that the heel doesn't get hung up on the cut. The slight arc give that heel clearance. I've made the mistake of having a Straight edge once....I had to regrind the profile. For me, and the way we cut, a slight arc helps alot.

Also, not sure if others mentioned..... Why are you canting the handle down?
That's what choppers do. For a chef knife I want hand clearance over cutting board.
Also take users height into consideration for handle to blade/cutting approach.

Super tall users, or super short users hold it at different angles.
 
Same reason as it is on Dalstrong Omega series which have some of my favorite handles of the many $100+ or slightly below that knives I own. Their Centurion and Delta Wolf series have it as well. It is not fully canted down, but is straight for the first almost 2 inches bit then curves down on my design. Another thing to consider is that the neutral position position of the hand is flat facing when in a pinch grip or even going at a slight downward angle in relation to the blade. If you tilt you hand up in relation to the blade in the pinch grip you will feel there is more tension in your wrist and is no longer in a more neutral position. This does not change whether you are taller or shorter, though in the case of someone being taller it may be beneficial to have an upward angled handle in order to get more leverage and have the blade at a better angle in relation to the board. For those that are smaller, they most likely will be using a stool to get to a comfortable height for cutting, so just above waist level and then it is not as much of an issue. I am 5' 9" and have had no issues with having that cant in the handle and find it actually pretty comfortable when it is well executed. I also went and was trying to use the knives as though I was taller and also smaller, and that is what I have found. I am going to try and bring those knives from those series and have some of my tall friends(6' 7") try them out and give feedback on what they think of it and then report back here. I will also bring the kitchen knife cutout I am going to get made of wood. I have access to a laser cutter so it should be easy to get that knife blank made just as soon as I draw it up on Fusion 360.It unfortunately is not strong enough to do steel, and only very lightly touches softer metals. It also depends on how tall the cutting surface is, whether it is a home kitchen countertop or a commercial prep table. Have you used a knife that has a handle like what is on those series? On this particular design I may need to flatten it a touch more as it is only flat for about 1.6" then curves downward. Also, do you think a 4.3" handle is a good size in relation to the blade, or make it a touch longer

As to your question on hand clearance, unless you are hammer fisting it instead of doing a proper pinch grip, most of your clearance comes from the blade height of which there should be no issue with on a 2" blade and then the blade angle in relation to the cutting board and handle. A downward angled handle will only have an impact on it from being angled down to far which would be uncomfortable anyways. Another brand to look at would be ErgoChef. There knives are all designed around having a hat sort of handle. This is what I have observed. The grips are one of the most important parts though, as your hand in the pinch grip sits on the first 2.5" - 4" depending on the balance point of the knife. That would be compared to a hammer grip that takes up most of the handle normally and does not provide nearly the same level of control, accuracy, and safety as a pinch grip with good bear claw technique. That being said, I have not actually made knives, just refurbished, sharpened, and thinned them. I do try to ask people about their experiences with knives, I do follow up with customers to see how well the edge is holding up to see if I need to do stuff better so they get a better lasting edge, and I try to use every knife I get and see how they feel in actual use. I am going to get the outline made in wood and see how that feels. If you have any good suggestions on what might help the handle function better, I am open, as it seems you have a good deal of experience in knife making and know what you are talking about. I also definitely agree on having it be completely flat on further thought, as I just tried a Tramontia professional chefs knife that has that and it sticks really bad on the rocking. I think a big part of it is the extra friction from more edge contact, and the other would be that more edge is able to bite I to the wood at once, and thus necessitates more force be used to rock it back and forth instead of being a smooth flow which comes from as said even a slight curvature that helps reduce how much edge is in contact with the board at any one time.On this particular knife I am going to try to have it centered just behind the transition line between the handle and the rest of the knife.

I was wondering if you have any experience working with Jarod, and then how good of a job does he do with doing heat treating? I have seen him, Pete's, and one more that have been recommended, and that people did not seem to have issues with.

And again, thanks for all the help and helpful critiques! I greatly appreciate it!

Sincerely,
JS
 
Last edited:
You must log in or register to reply here.
Back
Top