Thickness of a kitchen knife billet

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kaizo

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Oct 17, 2014
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Hi everyone I am in the process of buying some D2 for my kitchen knife project but what is the recommended thickness to start with? I am hoping to end up with 2.5mm (0.1 inch) but I don't know how much steel I would lose after sanding off the surface post-heat treating. 3.5mm Seems excessive but should I go that thick? I am hoping to have the edge to be a chisel grind (so like a Japanese knife but without the urasuki).

Thank you for your help :)
 
if you want to finish at .10 inch thick start with 1/8" stock, you dont really need to remove much for finish sanding. What state is your D2 in? If it is precision ground then you would only need sand a few thousandths off to finish.
 
timos- said:
if you want to finish at .10 inch thick start with 1/8" stock, you dont really need to remove much for finish sanding. What state is your D2 in? If it is precision ground then you would only need sand a few thousandths off to finish.
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Thank you for the reply :), I'm hoping to buy one off the mill so its the surface does need a nominal amount of sanding to bring out the satin shine but it shouldn't have any pits etc... so I think I can just get away with taking a little off.

I think it counts as precision ground but I'm not sure since I'm not familiar with knifemaking yet...
 
What type of knife are you making? .1" is pretty thick for many kitchen blades.
 
Stacy E. Apelt - Bladesmith said:
What type of knife are you making? .1" is pretty thick for many kitchen blades.
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Hi thanks for the reply the general knife shape is like the one below. I'm practicing first before one day making one for my uncle who is a chef and has a love for a nicely made knife. :)

16422667_10154832417291083_2708406090528825732_o.jpg
 
Do all of your shaping prior to heat treat! D2 can be taken pretty fine at first & then the actual finish after heat treat is really just finish sanding & polish. I didn't do this on my first blade (don't ask) & it took a lot of work to get it right, because D2 is so hard to finish once it's hardened. It was like finishing old concrete with 600 grit sand paper, at least it seemed that way at the time. Also, remember to do a HT with cryo after the high temp run-up in the furnace, since the RA can be huge when it's just quenched. The cryo really helps with D2 for finishing the hardening process & getting the best performance out of it.

I would also question D2 for a kitchen knife. It's a great steel, but might not be my first choice for working with a lot of acid foods (stainless?). Going with 0.10" is pretty thick as Stacy said, better to go with no more than 0.08" or even less for a finished blade, unless it's going to be a very large kitchen chopper with a lot of heft! A light, fine blade will be easier to wield for extended periods of time.
 
A light, fine blade will be easier to wield for extended periods of time
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is exactly right for a slicing kitchen knife. For anything up to 8" I like starting with .070" or so, then with a distal taper from handle to point for a really nice slicing knife.

If you're sending out for HT, I'd suggest something like AEB-L for lower cost, but some of the best value for money steels. JT right here on our forum does HT work at a very reasonable price.

Ken H>
 
Thank you both for your reply :)

I'm looking to outsource the heat treatment and my local one said £40 ($50) for 10kg min so I am looking for someone who is willing to do it for me on a small scale. I am hoping to find someone here in England to avoid issues at the customs but I may have to find someone in the US to help me out. Thanks for suggesting JT for me Ken. :)

I'll definitely look for a thinner stock than 0.1inch since its a slicer.

I chose D2 because its a nice steel and my local heat treatment does them on a daily basis but if I can get somebody else to do the heat treatment then I think its a better idea to go back to the drawing board. I do like elmax if I can get my hands on those...

Thanks again for the help everyone :)
 
After starting at 1/8", then .100", I realized these are too thick for a slicing knife. .100" OK for a heavy chefs. Recently made a slicer in .070" with some small taper towards the tip...very very happy with how it turned out. Will be using .070" from now on.
 
For all but the heaviest breakdown knives, I use .070" and thinner stock. wo descriptive terms used for kitchen knives are laser and chopper. The difference is mostly the thickness. A laser is thin, light, and fast as it slices through soft things, a chopper is thicker, heavier, and cuts by breaking the veggies apart as it cuts down through them.

Unless your uncle has specified one or the other, go with a thinner blade.
When I take an order from a chef, I discuss the use, preferences in grip, thickness, balance, handle type and material, and steel preferences with them before making any plans. Chefs are very specific in what they like .... and equally specific in what they hate. It is also a good idea to ask them to bring their favorite knife with them to show you what they like about it. You can take good measurements from it.
 
I will give some advice, you can take it or leave it.
Thin blades like kitchen knives need to be ground after heat treat becaus thy will warp and have a high chance of bacon edge. If you have a belt grinder this is not a problem but if not then it could be a tad more of an issue.
I love D2 for most everything but I also have made quite a few kitchen blades our of A2 and it preforms amazing. My new heat treat process on A2 will put the blade at 64rc with a 400° temper. The great thing about A2 and D2 is that it's very common and can be found in most thicknesses. In my experance I have found A2 to be a tad bit more susceptible to staining from food. But once it builds up the patina it's good to go and does not have a problem. I had a head scratcher a little while ago when the wife was cutting an apple. Every slice was leaving a black mark on the apple. But after cutting one Apple and letting the patina develop it was all good, now the blade is perfect. I don't see this problem with the D2 blades I make. People call D2 a semi stainless which is not really accurate because there is no suck thing. The steel is stainlees or not there is no semi technically speaking. But it's still rather good for a carbon steel.
 
I was always under the impression that D2 was a poor choice for fine edges such as those required on kitchen knives?
 
I'm going to be the voice of dissent as I have a few Japanese and Japanese style chef's knives or gyutos that start out thicker than 0.125" at the spine above the heel. I have a Devin Thomas 240 mm gyuto that measures about 0.125" at the spine above the heel, 0.100" at the spine about halfway then about 0.060" a little more than an inch before the tip, AND it's one of the best cutting kitchen knives that I have.

On the other hand, I don't believe Hoss does anything close to a simple full flat grind on his kitchen knives. If you're just going to do a full flat or a scandi grind with no distal taper, then thinner will probably work better. Of course, it also depends on what the Chef prefers his or her knife to do in the kitchen. I believe a lot of single bevel Japanese knives are fairly robust at the spine?
 
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I was looking at the specs for a 44mm wide 170mm Shigefusa and has a spine thickness of 3.3mm at the heel which is 1/8 inch on the nose, 2mm in the center and 1mm up by the tip, but those knives supposedly have a pretty heavily "scooped" S grind.
 
D2 can get a fine edge if it's heat treated to have one. It's not quite as good as A2 becaus of the carbides but if treated correctly it can be a damn fine slicer.
 
Thank you all very much for your help! I think from the sounds of it the best thing is to go for an A2 in 0.07inch. I do have a small belt grinder so I will put the edge on after heat treat. :)

I did ask him what knife he wanted and he showed me his favourite knife and I have taken an outline from it. Would the same rules apply with the thickness even if it is going to be a chisel grind?

Thank you all very much again for helping me the number of people coming out to help is nothing short of amazing. :)
 
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CPM D2 would probably be the better choice for a kitchen knife with fine edge. But in all reality, the edge can be made as fine as you want it with regular D2, provided you have the ability/patience to do it. ie good sharpening techniques and stones.
 
Thabk you for the advice. I've got a modest set of stones so I think I will give the knife a general edge using the belt grinder and work my way up from a low grit to high by hand. Thankfully chisel edge is very easy to shape into :)
 
i jsut needed to add my 2 cents ever kitchen knife i have made in the last 4 years has started as .103-.113 stock including parers the grind is much more important then the starting spine thickness onlny the smallest knives work well under .070 thick as once theye get bigger flex can be an issue (my single bevel knives are all over 1/8 inhc thick at the start )
 
Thats reassuring to hear Butch, Ive got some 52100 in .093" from Aldo coming in. It's mostly for some utility type blades but I planned on doing some paring knives as well in the 3-4" range. Flat ground with a blade hieght of 3/4ish" and a strong distal taper, we'll see how they go starting at .093".
 
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