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clovis
Posts: 50
I just saw the rather wonderful W&B in the marketplace. One line in the description particularly caught my eye:-

She was perhaps designed for tough whiskers and tender skin, with steel hard enough to hold an edge for a long time but not so hard to irritate the skin.

I have a two razors that often leave some redness on my throat, whereas I have no problem with any of my others. When honing these two razors however the slurry takes longer to go grey - I assume that indicates they wear more slowly because they are harder. Which brings me back to the sentence in the listing. Can anyone shed any light on how/why a harder steel may lead to irritation?
2011-11-19 15:24
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Emmanuel Giannoulakis (Emmanuel)
Advisor
From: Greece
Posts: 942
My friend i suggest to review your scent that the metal hardness effects the skin ,maybe
the edge you produced is not suitable for your skin concerning these specific razors.
The edges derived from coticules only ? Do you use any other support like crox or diamond paste ?
If not i assume that these razors are full hollow ground and you apply more pressure during honing
such that to make a harsh edge
The slurry darkness depends also of the quantity of the metal touching the hone surface and not only of the metal hardness.
If you have a magnification you have to watch the edges of the mentioned razors and the edge of another razor which is smooth to your skin.
Best regards
Emmanuel
Emmanuel Giannoulakis
from Athens Greece
2011-11-20 00:55
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Smythe
Advisor
From: United States
Posts: 990
Clovis, allow me to suggest that your suspicion is indeed correct. This post may be long and "wordy" but bear with me.
What you have is called “variances in manufacture”. There are variances in all stages of manufacture.

Variances in raw material: In the case of razor steel, the amount of carbon in the steel has an influence on the hardening characteristics of the steel, Even today, it is difficult to determine exactly how much carbon is in a sample of steel, and suppliers will state anywhere between .08 and .12 percent (hope I got those decimal places right)

Variances in treatment: After the blade is forged it must be hardened and then tempered by heat. The temperature of the heat also has an influence on the hardness, toughness and crystal structure of the blade and the resulting edge.

Many vintage cutlers didn’t have precision thermometers (thermocouples), so an experienced workman would gage the heat by looking at the changing colors of the blade as it is heated to determine when tempering was done… as it is human nature… he may be spot on in the morning just after breakfast… perhaps not so just before lunch.

Because of these variations (and others) a razor may be hard, medium or soft (and in this case, by “soft” I am not referring to a blade that “lost its temper” from overheating).

Hard Steel (hard blade) will resist abrasion, so that would explain why the slurry takes longer to darken. A hard blade will take a cutting edge, however hard steel tend to be brittle, and so there may be microscopic chips at the very edge, that would explain the skin irritation.

In the case of hard steel a suggested solution is to use a strip of tape on the spine, this will make the bevel angle more obtuse, the edge will have “strength from volume” and thus reduced micro-chipping (incidentally, a pasted strop may also do the same).

Soft Steel is easy to sharpen (relative to hard steel) so the slurry will darken faster (again relative to hard steel), and will tend to shave with less irritation. Some folks much prefer the “smooth?” shave offered by soft steel however, it will require more frequent touch-up than hard steel.

Medium Steel is somewhere in between the two, some folks will say it the best of both worlds.

Now I must mention there exists razors with Flawed Steel, and are less suitable for shaving live-human whiskers.
Steel that is Too Hard or Brittle, may not have been tempered sufficiently or its crystal structure may have been injured previously during forging or hardening. When sharpening such a blade, the edge will have tiny notches (chips) just visible to the naked eye, and despite your best efforts (and equipment) will not produce a clean notch-free edge… and as you can well imagine, the resulting shave will not be satisfactory. A solution to this condition may be possible, but it’s not worth the effort.

Steel that is Too Soft is at the other extreme, it may have “lost its temper” from over heating during polishing or grinding, or simply was not sufficiently hardened to begin with. Such steel is very easy to sharpen, but will often produce wire or “filmy edge” as if there is a fin attached to the edge. Such an edge if successfully sharpened will not hold a keen cutting edge for long. Again, as in steel that is too hard a solution is not worth the effort.

Finally… Don’t place too much faith in marketing BS from anyone who tries to sell you something. Believe me, they will tell you the item is virgin, rare and the best thing since sliced bread (hint: you need it, and you should quickly pay the premium to secure it before someone else gets the better of you).

But with that said, I believe razors for Tough Whiskers and Tender Skin will have a slightly thicker spine in proportion to the width of the blade, and the steel will be Hard or Medium tempered. Razors for Soft Whiskers and Tender Skin will have Medium to Soft temper. Of course for Soft Whiskers and Not-So-Tender Skin, almost any razor will do.

But as fate would have it... it is difficult to determine the hardness or softness of steel by looking at it, and equally difficult to determine the hardness or softness of whiskers or skin (relative to who:confused: )... so we should try different razors until that special one is found… then nothing else matters… of course, in so doing, it’s good to have a return guarantee… just in case. :thumbup:
2011-11-21 09:13
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Matt
Associate
From: Poland
Posts: 1047
Splendid write-up, Smythe. :thumbup:
"Very interesting indeed :) I did something similar with cheese a while ago" - Dr Ralfson
2011-11-21 14:05
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Deckard
Posts: 156
Smythe,
I know all about variation in process as I am a quality engineer by trade.
Hardness is just one factor that determines face feel and any combination of other stuff particularly bevel angle.
Anything over 50 Rockwell C will give a servicable edge to shave with, I personally would consider that to soft. Harder edges hold that edge longer but require to be honed in a way conducive to smoothness. Forging brings about it's own problems with thermal cycling which if you get steel to hot grain growth is a risk which is a bad thing for blades.
You could go on and on about optimal heat treat, etc, etc.
How on earth did they make perfectly good weapons in antiquity with simple technology, materials and processes?

Joe
2011-11-21 16:07
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Smythe
Advisor
From: United States
Posts: 990
Deckard,
Hardness is indeed only one part of the face-feel, but I took a chance and assumed he knows his way around a hone and his five razors. I figured all other things being equal, the only thing left is the variations in the razor steel… And considering all the above, I am willing to accept that I could be way off… no shame in that is suppose.

How did they make such perfectly good tools with what we now consider antiquated technology?...
… I suspect it’s because the human mind and body is an incredibly amazing piece of machinery, mostly because of Muscle Memory, and the ability to make corrections on the fly. In a manufacturing environment, division of labor makes efficient use of these attributes resulting in repeatable accuracy… it’s not perfect… but consider even today’s modern manufacturing processes often produce flawed products... with a complimentary warranty against defects.
2011-11-22 10:26
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Emmanuel Giannoulakis (Emmanuel)
Advisor
From: Greece
Posts: 942
iconSmythe:
Deckard,
Hardness is indeed only one part of the face-feel, but I took a chance and assumed he knows his way around a hone and his five razors. I figured all other things being equal, the only thing left is the variations in the razor steel… And considering all the above, I am willing to accept that I could be way off… no shame in that is suppose.

How did they make such perfectly good tools with what we now consider antiquated technology?...
… I suspect it’s because the human mind and body is an incredibly amazing piece of machinery, mostly because of Muscle Memory, and the ability to make corrections on the fly. In a manufacturing environment, division of labor makes efficient use of these attributes resulting in repeatable accuracy… it’s not perfect… but consider even today’s modern manufacturing processes often produce flawed products... with a complimentary warranty against defects.


My friend i agree with you in many places.But as i said its not the hardness that effects his skin but the produced edge after honing. I honed and tried a Zowada razor for a friend. As Zogada says
his razors touch the hardness of 63 rockwel. For me is a very hard steel ,although i found the honed on coticule edge very smooth.
Thank you for the previous excellent post.
Best regards
Emmanuel
Emmanuel Giannoulakis
from Athens Greece
2011-11-22 10:54
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BlacknTan
From: United States
Posts: 176
I've read many comments on the various boards about the hardness and heat treating of specific razors, and razors in general. How various manufacturers and artisan makers get their steel to specific numbers on the c scale. I worked as a Toolmaker since 1967, and recently retired, and unless the art has changed markedly in the last four years, the Rc number os steel will always be "within a range," and can vary in different areas along the surface.
I will add that I have no degree to back me up. I'm not a metallurgist or heat treating specialist. Only 40+ years of practical knowledge from the School of Hard Knox. We used to do some of our own heat treating, but most was sent out to professional heat treating houses with the proper equipment. Depending upon application, we would send specs of what we would desire with individual pieces of a die... most often we would spec 58-62 Rc. One rare occasion, things would come back out of spec, pointing up the difficulty in hitting a specific Rockwell number right on, even for familiy business that have been doing heat treating work for generations. It's an imperfect science at best, depending upon many factors.

So, when I read posts that state that some artisan razor or knife maker heat treat his blades to "X" number on the C scale, I always take such knowledge with a very large grain of salt.
Better a diamond with a flaw than a polished pebble...
2011-11-22 14:21
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Emmanuel Giannoulakis (Emmanuel)
Advisor
From: Greece
Posts: 942
iconBlacknTan:
I've read many comments on the various boards about the hardness and heat treating of specific razors, and razors in general. How various manufacturers and artisan makers get their steel to specific numbers on the c scale. I worked as a Toolmaker since 1967, and recently retired, and unless the art has changed markedly in the last four years, the Rc number os steel will always be "within a range," and can vary in different areas along the surface.
I will add that I have no degree to back me up. I'm not a metallurgist or heat treating specialist. Only 40+ years of practical knowledge from the School of Hard Knox. We used to do some of our own heat treating, but most was sent out to professional heat treating houses with the proper equipment. Depending upon application, we would send specs of what we would desire with individual pieces of a die... most often we would spec 58-62 Rc. One rare occasion, things would come back out of spec, pointing up the difficulty in hitting a specific Rockwell number right on, even for familiy business that have been doing heat treating work for generations. It's an imperfect science at best, depending upon many factors.

So, when I read posts that state that some artisan razor or knife maker heat treat his blades to "X" number on the C scale, I always take such knowledge with a very large grain of salt.


Cheers Blackn Tan
Best regards

Emmanuel
Emmanuel Giannoulakis
from Athens Greece
2011-11-22 17:37
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Emmanuel Giannoulakis (Emmanuel)
Advisor
From: Greece
Posts: 942
iconclovis:
I just saw the rather wonderful W&B in the marketplace. One line in the description particularly caught my eye:-

She was perhaps designed for tough whiskers and tender skin, with steel hard enough to hold an edge for a long time but not so hard to irritate the skin.

I have a two razors that often leave some redness on my throat, whereas I have no problem with any of my others. When honing these two razors however the slurry takes longer to go grey - I assume that indicates they wear more slowly because they are harder. Which brings me back to the sentence in the listing. Can anyone shed any light on how/why a harder steel may lead to irritation?


Clovis the thread is going well .Kindly requested photos and description of mentioned razors.
Best regards
Emmanuel
Emmanuel Giannoulakis
from Athens Greece
2011-11-22 17:45
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Dr Ralfson Bwhahaha (tat2Ralfy)
Associate
Posts: 3610
It is my experience that "harder" steels are harder to hone to the very max, and if the edges show no sign of microchips, it is usually the fact that the edge is slightly behind in the finish that causes irritation.

I have a couple of razors that are the hardest razors I have ever honed, they were both a pain to get right, however they now deliver the smoothest of shaves.

Regards
Ralfson (Dr)
We Are All Pioneers In Our Own Right.
The Infamous Coticule Crew
Pip Pip Old Bean
2011-11-22 21:21
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shaved
Posts: 28
Unless you're Chuck Norris and eat carbides for breakfast you'll no be
able to use your skin for testing metal hardness.

Just try to tame these blades.
Why do we hide from the police dad?
They don't use crox son. We do.
2011-11-23 00:17
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Smythe
Advisor
From: United States
Posts: 990
iconEmmanuel:
iconSmythe:
Deckard,
Hardness is indeed only one part of the face-feel, <SNIP>... with a complimentary warranty against defects.


My friend i agree with you in many places.But as i said its not the hardness that effects his skin but the produced edge after honing. I honed and tried a Zowada razor for a friend. As Zogada says
his razors touch the hardness of 63 rockwel. For me is a very hard steel ,although i found the honed on coticule edge very smooth.
Thank you for the previous excellent post.

Best regards
Emmanuel

Thanks for the compliment my friend... But I must insist that steel hardness does indeed affect the quality of the shave… it is indirect.

There should not be a need to say this as it is common knowledge… There are MANY reasons for an uncomfortable shaving edge. And I am stating: Hardness of the Razor Steel is ONLY ONE reason.

The further away the steel form “ideal hardness”, the more effort it requires to produce a comfortable shaving edge… and this statement is true for whatever equipment you have available, or years of experience.

What that means?
It is human nature to learn and adapt to changing conditions… so even if the razor steel is far from ideal, with enough effort, one may cleverly work around the defects and result in a comfortable shaving edge.

This also means?
If the effort for a successful result is worth it, then it is all good for person who sharpens and shaves with the razor, AND, if the effort is NOT worth it for the same success, then it is still a valuable learning experience (two positives).

So i say again... Yes sir, the hardness does indeed affect the comfort of the edge, but that comfort will depend on how much effort is expended to compensate for the variances of the steel… and based on my analysis of the Original Posters question, I suggest ONE POSSIBLE solution: that adding a strip of tape to the spine will increase the bevel angles and may result in a more comfortable edge.

A bit off topic… (no offense my friend Emmanuel) but here we come to one of my pet peeves… the great Buffoon Language of Rockwell Numbers.

As I see it, these numbers are often banded about by folks, who feel the need to impress those with little understanding, the properties of hardened steel. Perhaps 99.9% of us common folk only understand higher numbers means the harder steel. So it’s no surprise that higher/bigger number make a bigger impression on us all. I suppose Robin would say… “It’s amusing to hear grown men quote Rockwell Numbers, sounding like horny-prepubescent-girls, huddled together in the school's public toilet, comparing notes on their boyfriend’s penis sizes”.

The funny thing is… hardening and tempering carbon steel for razors is not “Precision Engineering” at all. In fact, vintage smiths used no more than a coal burning hearth and leather bellows to produce countless fully functional razors with shaving qualities as good as… and in some cases better than those produced today in modern ovens equipped with precision thermal control. Indeed, the process does require experience, but no more than that required for a working knowledge of any type of new endeavor. In all new endeavors, we all start from zero, but the good news is, we never stop learning till the day we die.

Correct me if I am wrong, but I suspect no razor manufacturer or cutler (alive or dead) quotes the hardness numbers of their products… perhaps TI, for one of their new models, but then, TI also extensively use buffing machines to mirror polish some of their razors… something i don't believe vintage razor manufacturer did… But perhaps… for better or worse… it’s time for old beliefs to step aside for the changing times.

The above is not meant to belittle the value of hardness numbers; they do have their place in precision tool manufacturing. But there is no reason for any reputable open razor maker to quote hardness numbers… but for want of the shepherd to impress the sheep.
2011-11-24 01:41
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clovis
Posts: 50
Emmanuel - through my work I spend extended periods in different locations, so unfortunately only have the Sheffield razor with me, the other is at home so can't get pictures. I took some photos of the Sheffield just now but they are pretty poor, so I plan to take some tomorrow in daylight and post those in the hope they'll come out better. Watch this space....
2011-11-24 15:29
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clovis
Posts: 50
Picture of the 'hard' Sheffield - about the best quality pics I think I'm going to get without serious work on my camera skills.

Razor overall



Blade face



Blade back



There are some watermarks visible. Looking at the edge under a 3" magnifying glass (x5 perhaps?) I was unable to resolve any visible discontinuities, or any significant scratches it looks basically smooth & uniform.
2011-11-25 16:47