How far to grind bevels to the scribe lines

R

remfallen

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Jan 2, 2024
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Goodmorning! So yesterday I put bevels on two blanks that I’ve been working on, and realized that I made the edge to thin since they have yet to be heat treated. I brought them down to about .01-.02. I didn’t do this intentionally, however I thought that I was suppose to take the bevel down until the sharpie disappeared, and my bevel met the scribe line. Ive noticed this leaves me with to skinny of an edge for heat treat, but im confused at what point should I know to stop if I can’t bring the bevel down to the scribe lines on both sides. Should I just start grinding after heat treat and make sure to take me time and keep it cool? Working with 1095 right now. Thanks!
 
With simple carbon steels like 1095 etc I like to leave around 0.04" before heat treating. This leaves plenty of room to correct little warps and grinding that type of steel post heat treatment isn't difficult. I basically just take a little meat off pre heat treatment to make life a little easier after heat treating. I also leave around 0.1" of flats for the same reason of giving myself space to correct things post heat treatment.
 
What he said.
I made that mistake years ago when I first started messing around with knives and ended up with a bacon like edge.
 
Robert Erickson said:
With simple carbon steels like 1095 etc I like to leave around 0.04" before heat treating. This leaves plenty of room to correct little warps and grinding that type of steel post heat treatment isn't difficult. I basically just take a little meat off pre heat treatment to make life a little easier after heat treating. I also leave around 0.1" of flats for the same reason of giving myself space to correct things post heat treatment.
Click to expand...
Awesome I appreciate the replies guys. So in doing so, do you try to make your scribe lines wider apart? I guess my disconnect is if I bring the bevels down to the scribe lines, im left with no more than .02. Im using an 1/8 drill bit on 1/8 stock to scribe. Should I just continue making the same scribe lines and just simply not bring the bevels all the way down to them? The only issue with that i can see is having uneven space on both sides of the scribe lines.
 
Are you saying that your steel thickness is 1/8" thick?

Me personally, i like to grind my bevels Hard, after heat treating. Especially at thinner stock.

Grinding hard is a little slower, but you have more time to react, and it takes longer to screw something up....
and my theory is that you need alot of time to get good at something. So since it takes longer to grind hard, you will get better at it Faster.

Also, some steels are just gummy.
and it feels easier/cleaner grinding those at a harder state.
 
On thinner stock like that, especially with 1095 etc, it would be fine to just profile and drill pin holes and grind it all post heat treatment.

Or scribe with a smaller drill bit then flip the blade and scribe again. That will give you a better idea when to stop and leave more meat at the edge.
 
Crag the Brewer said:
Are you saying that your steel thickness is 1/8" thick?

Me personally, i like to grind my bevels Hard, after heat treating. Especially at thinner stock.

Grinding hard is a little slower, but you have more time to react, and it takes longer to screw something up....
and my theory is that you need alot of time to get good at something. So since it takes longer to grind hard, you will get better at it Faster.

Also, some steels are just gummy.
and it feels easier/cleaner grinding those at a harder state.
Click to expand...
Yes my steel thickness is 1/8" thick. I may just try and do the beveling after heat treat.
 
Robert Erickson said:
On thinner stock like that, especially with 1095 etc, it would be fine to just profile and drill pin holes and grind it all post heat treatment.

Or scribe with a smaller drill bit then flip the blade and scribe again. That will give you a better idea when to stop and leave more meat at the edge.
Click to expand...
Awesome I appreciate the info!!
 
I used to scribe with drill bits and would have used a smaller one and flipped it to make two lines. Now I have a height gauge from Amazon that I use to scribe lines at any height I wish. I put a center line and two other lines as guides prior to heat treatment. I like the center line as a guide after heat treatment.
 
When using a drill to scribe the center lines you use one a few hundredths smaller that the steel thickness. Scribe one line and flip the blade over. Scribe again. Now you have two parallel lines to grind towards. For every .01" less than the steel thickness the two lines will be .02" apart. So, if you want the edge to be .040" on a piece of 1/8"/.125" steel, use a #36 or #37 bit (about .105"). Realize that steel marked 1/8" will be anything from .120 to .150". Unless precision ground it almost surely won't be .125". Most steel comes about .015" oversize.
For no-warp exact-thickness steels, order precision flat ground stock. This is what many folder makers use. However, if you are grinding bevels and all other features on a blade you will end up grinding nearly every surface, so you really only need flat-ground stock. Most of us don't even get that unless the steel will be hardened as a bar with no profiling.

It really doesn't matter how much the lines are apart, though. They are a guide in grinding the bevels. You can grind to a nearly sharp edge and then just "dull" the edge back a minute amount to get the desired edge thickness per-HT. A few strokes with a fine-cut file will drop the edge back to .040".

TIPs:
1) Make or buy an edge scriber. It will follow the edge regardless of any warp. This will give the best edge lines for grinding.

2) When starting the bevels, grind the edge at about 45° to the scribe lines (I take it to the center). This gives a visual reference of how much you need to tilt the blade to make the bevels go from the top of the grind to the edge. It also greatly preserves the visual center line. You can accidentally grind past a scribed line, and they can be hard to see sometimes.

3) Final tip to a new maker - Get a cheap $10 micrometer from HF or Amazon. Measure a bunch of knives in your kitchen, your pocketknives, and some commercial hunting knives (you can look those thicknesses up online.). You will quickly find out that 1/8" steel is twice as thick as most all knives. Kitchen knives range from .040" to .060". Hunting knives are .060" to .010". Pocketknives range from .050" to .090". This is why many of us don't grind any bevels before HT. If Iam making a .060" thick kitchen knife from .070" stock, and I wanted the edge to be .040" before HT ... I don't need to grind any bevels before HT.
Too thick is probably the number one thing wrong with most first (and sometimes 100th) knife. It affects weight, balance, ergonomics, and cutting ability. You want fat to chop and thin to cut. Distal taper is also very important on most knives, and it will allow for somewhat thicker stock, but no one really wants a .125" thick tang on a chef's knife.

4) Many new makers learn to grind a perfect bevel with the "Bubble Jig" IT is a bevel angle measuring tool used to grind the bevels by showing you a bubble to watch as you grind. The maker, Fred Rowe, sells them in The Exchange ,as a very reasonable price.


Final comment on new knives being too thick and heavy - I had a machinist ask me to look over his knife that he made 100% on the mill. He made a beautiful bolster release auto. It had a razor sharp 4" blade that was .200" thick. The blade and frame were O-1. The scales were milled from 1/4" thick carbon fiber. The knife was about 1" thick side to side. It was very heavy (I have made large hunting knives that weighed less). When asked to critique it I complimented him on his machining skills and precision fit and finish. I said the blade's length and thickness, knife overall thickness, and weight were serious issues, though. He replied that he wanted it strong and didn't want it to ever break. I agreed that he was right about that, because no one would carry a 1/2 pound knife in their pocket.
 
Stacy E. Apelt - Bladesmith said:
When using a drill to scribe the center lines you use one a few hundredths smaller that the steel thickness. Scribe one line and flip the blade over. Scribe again. Now you have two parallel lines to grind towards. For every .01" less than the steel thickness the two lines will be .02" apart. So, if you want the edge to be .040" on a piece of 1/8"/.125" steel, use a #36 or #37 bit (about .105"). Realize that steel marked 1/8" will be anything from .120 to .150". Unless precision ground it almost surely won't be .125". Most steel comes about .015" oversize.
For no-warp exact-thickness steels, order precision flat ground stock. This is what many folder makers use. However, if you are grinding bevels and all other features on a blade you will end up grinding nearly every surface, so you really only need flat-ground stock. Most of us don't even get that unless the steel will be hardened as a bar with no profiling.

It really doesn't matter how much the lines are apart, though. They are a guide in grinding the bevels. You can grind to a nearly sharp edge and then just "dull" the edge back a minute amount to get the desired edge thickness per-HT. A few strokes with a fine-cut file will drop the edge back to .040".

TIPs:
1) Make or buy an edge scriber. It will follow the edge regardless of any warp. This will give the best edge lines for grinding.

2) When starting the bevels, grind the edge at about 45° to the scribe lines (I take it to the center). This gives a visual reference of how much you need to tilt the blade to make the bevels go from the top of the grind to the edge. It also greatly preserves the visual center line. You can accidentally grind past a scribed line, and they can be hard to see sometimes.

3) Final tip to a new maker - Get a cheap $10 micrometer from HF or Amazon. Measure a bunch of knives in your kitchen, your pocketknives, and some commercial hunting knives (you can look those thicknesses up online.). You will quickly find out that 1/8" steel is twice as thick as most all knives. Kitchen knives range from .040" to .060". Hunting knives are .060" to .010". Pocketknives range from .050" to .090". This is why many of us don't grind any bevels before HT. If Iam making a .060" thick kitchen knife from .070" stock, and I wanted the edge to be .040" before HT ... I don't need to grind any bevels before HT.
Too thick is probably the number one thing wrong with most first (and sometimes 100th) knife. It affects weight, balance, ergonomics, and cutting ability. You want fat to chop and thin to cut. Distal taper is also very important on most knives, and it will allow for somewhat thicker stock, but no one really wants a .125" thick tang on a chef's knife.

4) Many new makers learn to grind a perfect bevel with the "Bubble Jig" IT is a bevel angle measuring tool used to grind the bevels by showing you a bubble to watch as you grind. The maker, Fred Rowe, sells them in The Exchange ,as a very reasonable price.


Final comment on new knives being too thick and heavy - I had a machinist ask me to look over his knife that he made 100% on the mill. He made a beautiful bolster release auto. It had a razor sharp 4" blade that was .200" thick. The blade and frame were O-1. The scales were milled from 1/4" thick carbon fiber. The knife was about 1" thick side to side. It was very heavy (I have made large hunting knives that weighed less). When asked to critique it I complimented him on his machining skills and precision fit and finish. I said the blade's length and thickness, knife overall thickness, and weight were serious issues, though. He replied that he wanted it strong and didn't want it to ever break. I agreed that he was right about that, because no one would carry a 1/2 pound knife in their pocket.
Click to expand...
Outstanding! Thank you so much for all of the info!
 
On 1095, 26c3, 8670, etc I like to grind down to about .03 approximately 1/4 inch up from the edge.
 
Stacy E. Apelt - Bladesmith said:
When using a drill to scribe the center lines you use one a few hundredths smaller that the steel thickness. Scribe one line and flip the blade over. Scribe again. Now you have two parallel lines to grind towards. For every .01" less than the steel thickness the two lines will be .02" apart. So, if you want the edge to be .040" on a piece of 1/8"/.125" steel, use a #36 or #37 bit (about .105"). Realize that steel marked 1/8" will be anything from .120 to .150". Unless precision ground it almost surely won't be .125". Most steel comes about .015" oversize.
For no-warp exact-thickness steels, order precision flat ground stock. This is what many folder makers use. However, if you are grinding bevels and all other features on a blade you will end up grinding nearly every surface, so you really only need flat-ground stock. Most of us don't even get that unless the steel will be hardened as a bar with no profiling.

It really doesn't matter how much the lines are apart, though. They are a guide in grinding the bevels. You can grind to a nearly sharp edge and then just "dull" the edge back a minute amount to get the desired edge thickness per-HT. A few strokes with a fine-cut file will drop the edge back to .040".

TIPs:
1) Make or buy an edge scriber. It will follow the edge regardless of any warp. This will give the best edge lines for grinding.

2) When starting the bevels, grind the edge at about 45° to the scribe lines (I take it to the center). This gives a visual reference of how much you need to tilt the blade to make the bevels go from the top of the grind to the edge. It also greatly preserves the visual center line. You can accidentally grind past a scribed line, and they can be hard to see sometimes.

3) Final tip to a new maker - Get a cheap $10 micrometer from HF or Amazon. Measure a bunch of knives in your kitchen, your pocketknives, and some commercial hunting knives (you can look those thicknesses up online.). You will quickly find out that 1/8" steel is twice as thick as most all knives. Kitchen knives range from .040" to .060". Hunting knives are .060" to .010". Pocketknives range from .050" to .090". This is why many of us don't grind any bevels before HT. If Iam making a .060" thick kitchen knife from .070" stock, and I wanted the edge to be .040" before HT ... I don't need to grind any bevels before HT.
Too thick is probably the number one thing wrong with most first (and sometimes 100th) knife. It affects weight, balance, ergonomics, and cutting ability. You want fat to chop and thin to cut. Distal taper is also very important on most knives, and it will allow for somewhat thicker stock, but no one really wants a .125" thick tang on a chef's knife.

4) Many new makers learn to grind a perfect bevel with the "Bubble Jig" IT is a bevel angle measuring tool used to grind the bevels by showing you a bubble to watch as you grind. The maker, Fred Rowe, sells them in The Exchange ,as a very reasonable price.


Final comment on new knives being too thick and heavy - I had a machinist ask me to look over his knife that he made 100% on the mill. He made a beautiful bolster release auto. It had a razor sharp 4" blade that was .200" thick. The blade and frame were O-1. The scales were milled from 1/4" thick carbon fiber. The knife was about 1" thick side to side. It was very heavy (I have made large hunting knives that weighed less). When asked to critique it I complimented him on his machining skills and precision fit and finish. I said the blade's length and thickness, knife overall thickness, and weight were serious issues, though. He replied that he wanted it strong and didn't want it to ever break. I agreed that he was right about that, because no one would carry a 1/2 pound knife in their pocket.
Click to expand...

Stacy, Your Tip #2. So many people say to do This.... I still haven't figured out Why? I've wanted to ask this for a Long time. I see it said alot as common knowledge and the thing to do, but idk why?

Is it something I just have to try, and then it will make sense???

Since you have to grind angles anyway.... why not just grind the Correct primary one first. Seems like fussing around grinding to your lines and such, just to have to do it over again, but then at a completely different angle?

What's magical about the 45 degrees?

I've been just grinding mine to what I want, right away..... After heat treatment.
Thanks.
 
Fitzo has the main points.
1) It is easier on the belts later on after hardening.
2) It is much easier to see an apex than two thin and possibly not distinct lines.
3) In tapering the bevels, it isn't just a single angle you grind (or a convex). The angle changes as the blade tapers both in thickness and height. With the spine a constant point and the V-edge a constant point, all you need to do is connect the two and BINGO, you have a perfect bevel. This is why I do not like people learning to make bevels on a jig. It will get you there part way but won't teach you how to freehand grind the rest. Many blades would be impossible on a jig.

Grinding the flat blade blank edge into an apex does not require any specific angle. Just make a "V" out of the edge with the apex in the center. 45° is just an approximate angle that will be fast and easy to do. The human eye can see some angles very accurately - they are 45° 90°, and 180°.
 
Stacy E. Apelt - Bladesmith said:
Fitzo has the main points.
1) It is easier on the belts later on after hardening.
2) It is much easier to see an apex than two thin and possibly not distinct lines.
3) In tapering the bevels, it isn't just a single angle you grind (or a convex). The angle changes as the blade tapers both in thickness and height. With the spine a constant point and the V-edge a constant point, all you need to do is connect the two and BINGO, you have a perfect bevel. This is why I do not like people learning to make bevels on a jig. It will get you there part way but won't teach you how to freehand grind the rest. Many blades would be impossible on a jig.

Grinding the flat blade blank edge into an apex does not require any specific angle. Just make a "V" out of the edge with the apex in the center. 45° is just an approximate angle that will be fast and easy to do. The human eye can see some angles very accurately - they are 45° 90°, and 180°.
Click to expand...

Maybe because since I don't use a jig, I freehand my bevels. I haven't noticed the apparent need to first do an additional bevel?

I'm curious what a poll would be on how many makers do that first?

Thanks.
 
I think it's what most people do.

If you want to see something a bit more strange, check out this hollow grinding video. He starts with a series of scallops.
.
 
Richard338 said:
I think it's what most people do.

If you want to see something a bit more strange, check out this hollow grinding video. He starts with a series of scallops.
.
Click to expand...
I've been watching him for quite awhile.....

He is one of the few Youtubers I can stand.

When I grind large amounts off, I scallop too, I was just doing it the other day grinding profiles.
Big Nibble by big Nibble, then blend
 
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