Thread: First Straight Razor Build (A learning Process)

1/8 is too thin. There is a formula around here for thickness to width. As I recall it is somewhere around 15 to 19 degrees angle on the bevel. You can do the math or search out the formula. ( In case I don't find it for you ) From my reading and being in the same boat as you I started with O1. I have some RSO's but have yet to finish enough to start heat treating. Which I may also have done by pro the first time. To anxious to have one of my own made and use it to mess up 6 blades learning to heat treat. Mike Blue is THE guy to listen too when it comes to steel. If I lived where you do I would probably be camped on his shop doorstep :<0)

Okay I found a place to start. I got 1/4 " stock and took it down to 3/16 for a 5/8 blade. Shooting from the hip is my style, checking for accuracy after.

http://straightrazorpalace.com/advan...pers-tape.html

Thickness of the spine should be 1/3 to 1/4 of the width. Don't don below 1/4 because you'll end up with something that looks like a razor but won't work.

EDIT: Copied from an earlier post of mine, in a similar thread about making a razor.


You want to taper the handle as well. Under no circumstances should you have a tang /handle that is
exactly as wide as the spine.
Once you start honing, the spine will get thinner. Not by a lot, but still. When this happens, you still want the blade to be perfectly flat on the hone. For this to happen, the tang / handle should never touch the hone, or you will get a sloping transition where the spine (and thus the edge) will always 'wobble'.

With knives you often see a small notch between the edge and the bolsters. this is for the same reasons: to make sure that the beginning of the edge will always touch the stone properly.

Also the following things:

- you don't want the tang to end in perfectly sharp corners, because you will scratch up a lot of things in the bathroom. the only sharp thing should be the edge
- get used to measuring things in empirical units. As much as I live in a metric country anduse the metric system for everything, the razor world operates in units of 1/16 inch for measuring the width and thickness of a razor. For lengths it's inches. Everything will go a lot smoother if you measure width in 1/8 or 1/16.
- carbon steel is perfectly fine for a razor. No need to consider it 'making do'. A razor is not subject to stress, fatigue, etc. The only thing that matters is the ability to take an edge and be relatively easy to hone. high carbon tool steel is a perfect steel for a razor. If anything, the challenge is to achieve the same level of edge quality with stainless, not the other way around.
- for the thickness you want to aim between 1/4 to 1/3 for the thickness vs width ratio. do not go smaller because your razors will be difficult to hold and lose its edge relatively quickly. In your case for 22 mm of width (~7/8") you want a stock thickness of close to 1/4"
- Leave the edge 1/16 before heat treatment, and grind away the rest of the hollow after quench and tempering.
- You need to grind the hollow so close that during honing, the bevels are uniform, and very thin. Ideally, the bevels should be a very thin, almost invisible line. A wide and uneven bevel is the sign of sloppy workmanship, and often indicates that only minimal post HT ginding was done.

Originally Posted by Bruno

EDIT: Copied from an earlier post of mine, in a similar thread about making a razor.


You want to taper the handle as well. Under no circumstances should you have a tang /handle that is
exactly as wide as the spine.
Once you start honing, the spine will get thinner. Not by a lot, but still. When this happens, you still want the blade to be perfectly flat on the hone. For this to happen, the tang / handle should never touch the hone, or you will get a sloping transition where the spine (and thus the edge) will always 'wobble'.

With knives you often see a small notch between the edge and the bolsters. this is for the same reasons: to make sure that the beginning of the edge will always touch the stone properly.

Also the following things:

- you don't want the tang to end in perfectly sharp corners, because you will scratch up a lot of things in the bathroom. the only sharp thing should be the edge
- get used to measuring things in empirical units. As much as I live in a metric country anduse the metric system for everything, the razor world operates in units of 1/16 inch for measuring the width and thickness of a razor. For lengths it's inches. Everything will go a lot smoother if you measure width in 1/8 or 1/16.
- carbon steel is perfectly fine for a razor. No need to consider it 'making do'. A razor is not subject to stress, fatigue, etc. The only thing that matters is the ability to take an edge and be relatively easy to hone. high carbon tool steel is a perfect steel for a razor. If anything, the challenge is to achieve the same level of edge quality with stainless, not the other way around.
- for the thickness you want to aim between 1/4 to 1/3 for the thickness vs width ratio. do not go smaller because your razors will be difficult to hold and lose its edge relatively quickly. In your case for 22 mm of width (~7/8") you want a stock thickness of close to 1/4"
- Leave the edge 1/16 before heat treatment, and grind away the rest of the hollow after quench and tempering.
- You need to grind the hollow so close that during honing, the bevels are uniform, and very thin. Ideally, the bevels should be a very thin, almost invisible line. A wide and uneven bevel is the sign of sloppy workmanship, and often indicates that only minimal post HT ginding was done.

That's a lot of good info to digest. Let me read this over a few times and stew on it. Thanks again!

And stay away from 52100 if you don't HAVE to use it for razors. Yes, it's good steel, and can stand a lot of abuse. But for a straight razor, those qualities are not needed, and will make it a lot harder to hollow grind the blade.

Originally Posted by Bruno

And stay away from 52100 if you don't HAVE to use it for razors. Yes, it's good steel, and can stand a lot of abuse. But for a straight razor, those qualities are not needed, and will make it a lot harder to hollow grind the blade.

Thanks, that one is off the list then. I think that ATS-34 is off the list as well (at least for now). I don't need stainless.

I wondered about this, but don't understand the relationship. The below sketch is not to scale, but what does spine thickness have to do with edge angle?

Originally Posted by DVW

I wondered about this, but don't understand the relationship. The below sketch is not to scale, but what does spine thickness have to do with edge angle?

Because a razor always, Always ALWAYS is honed with the spine on the stone.
Did I say always? I meant ALWAYS

The only way to develop a razor edge is with the spine on the stone so that you always get the right angle. Freehanding or something else just doesn't work. A razors edge is measured in micrometers and that is only possible if the spine is on the stone, and the spine with is between 1/3 and 1/4 of the width.

I think that I understand now. The ratio between the width of the blade and the thickness of the spine act as a "built-in" angle guide for honing. Again the sketch is not to scale, but this is how I am understanding this. Thanks. I will start off with 1/4 inch thick steel.

Since nobody has made any other comments about the shape or size of the blade, then I am assuming that it is decent as long as I use ¼ inch thick steel. So I picked up some Basswood at the local hobby store and made a pattern to trace onto the steel. Mike Blue had some great advice on the type of steel to use. Since I have some old car springs (5160) laying around, that is what it will be made out of. Mike assures me that, if I do my part correctly, the steel will perform well as a razor. I haven't done any forging in about 20 years as I have been buying flat bar. My “current” forge is not completed so I guess that I will just have to make due.