Yes, I mean the double wheel grinder.
It must be really skilled workers and good tolerances and setup of the wheels.
Or high percent of rejects.
Hollowest of the Hollow
- Thread starter Acmemfg
- Start date
Yes, I mean the double wheel grinder.
It must be really skilled workers and good tolerances and setup of the wheels.
Or high percent of rejects.
- Thread starter
- #22
Looked around some...amazing how quickly data can be accumulated these days. During the search process the words of Dorothy Gale came to mind..."If you can't find what you're looking for in your own backyard...."
Well put
Went back to take another look at a blade I have had on my radar for a long, long, time.
Shoulderless Ralf Aust..
Hollow as a carpetbagger's promise. Sometimes indeed it's all right in front of you.
Well put
Went back to take another look at a blade I have had on my radar for a long, long, time.
Shoulderless Ralf Aust..
Hollow as a carpetbagger's promise. Sometimes indeed it's all right in front of you.
Another vote for the Fili 14. Or just about any other 14 stamped blade.
That pic Doc226 put up is so thin I dont think you could find thinner. I bet you could almost see light thru it. ha.
The very thinnest razor I have is an old vintage blade I etched purposely to thin it. It measures .003" to .004" behind the bevel - right around the thickness of a piece of paper. Most razors are closer to .006" to .007" behind the bevel. One caveat of very thin/hollow blades - care must be taken to use absolutely minimal pressure when honing, because the apex will flex away from the hone immediately with even slightly too much pressure. They surely do sing though.
That is serious flexing!
Did you manage to get it equally sharp as other straights?
Does it feel any different to shave with?
Did you manage to get it equally sharp as other straights?
Does it feel any different to shave with?
Well, That is surely thin!
Steve56
Ask me about shaving naked!
I wouldn't bet my life on that.
Some various Swedish razors from >WWI-<WWII seem thinnest overall to me, and Filly-14 def. has what I'd consider the largest % of area where it seems it could be no hollower out of classically formed modern razors. But there is more to this than just that if you ask me; you also should consider the final angle of the bevel planes as dictated by the spine. The Filly's thick spine = a cutting angle slightly more obtuse than some others; any razor as wide and with a narrower spine will be more acute. It might not even be a bad thing, though, and you know assuredly that blade will flex nicely; if both are sharp as sharp the more acute bevel with thicker metal behind will not, in my opinion, flex as well as the more obtuse-beveled piece with great reduction of metal rearward.
Your post prompted me to measure a few of the razors I have here.
There are four Sheffields in the quick selection I made - an Isaac Ellis and a John Clarke & Son that I measured at 0.0065", a George Butler at 0.008" a Joseph Rodgers 13/16 at 0.0055" The Brevier (Le Grelot 363) came in at 0.0065"
Could turn into a "how-low-can-you-go?" competition!
C.
Heh, doubt anyone's going to beat .003" to .004" - that's getting to the point where honing is an exercise in patience. Thinner than that would be very tough to hone indeed. It would also probably be dangerous to shave with. When they get too thin, the razor can flex to a steeper angle when it grabs a hair and cut right in or at least cause bad razor burn. The razor gets as sharp as any other, but it does take some time to get there, and it's best finished on a fairly fast stone like a JNat.
For production razors, the thinnest I've ever measured was .005" behind the bevel. There's a reason the vast majority of razors measure .006" to .007" - manufacturers found that to be the best thickness compromise between ease of honing and ability to not flop around too much while shaving.
For production razors, the thinnest I've ever measured was .005" behind the bevel. There's a reason the vast majority of razors measure .006" to .007" - manufacturers found that to be the best thickness compromise between ease of honing and ability to not flop around too much while shaving.
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Yes quite so. I was amazed to discover today therefore, that long ago, those wonderfully skilled men could make a reliable razor that was as thin as seven thous. It's a wonder that more are not found to be cracked, given how hard the steel has to be to function properly. Fascinating stuff.
C.
BTW, not sure how many are aware of this already, but no matter the hardness or even alloy of a razor's steel, they will all flex the same amount for equal dimensions and equal applied force. In other words, a razor at 65Rc hardness will flex exactly the same as one at 55Rc, so long as they are equal thickness and equal width and equal force is applied to the same point, etc.
All steel has nearly identical Young's modulus (modulus of elasticity) no matter the hardness. Where hardness makes a difference is in yield strength - once softer steel is deflected to a certain point, it will take a permanent set, or be bent permanently. Harder steel will still spring back from this point and return to straight. The harder the steel, the further it can be deflected and still return to its original position with no permanent bend. The danger for these harder steels is then fracturing/cracking, as alluded to by Cambouis.
All steel has nearly identical Young's modulus (modulus of elasticity) no matter the hardness. Where hardness makes a difference is in yield strength - once softer steel is deflected to a certain point, it will take a permanent set, or be bent permanently. Harder steel will still spring back from this point and return to straight. The harder the steel, the further it can be deflected and still return to its original position with no permanent bend. The danger for these harder steels is then fracturing/cracking, as alluded to by Cambouis.
I just came for the pictures, and ended up learning something instead. Awesome thread guys!
Are you measuring directly behind the bevel. That measurement is important as it dictates the bevel width, but IMO the thickness a 1/4" back from the edge in combination with the measurement at the back of the bevel will describe the flexibility more accurately.
The tool's use precedes WWI and in fact is the current definition to the Germans of whether the razor is 'full' hollow; without that device then they think of them as only half hollow. For their defined extra hollow, they use the same device with smaller-diameter wheels. To them, no razor thereafter is truly straight; not like when only one side is being ground at a time, anyway. And another cool tidbit; any honing done after this device, to them, has one critical deviation vs all that came before. Note their definitions only consider the processes imparted, not what is being discussed here (which to my mind is the more relevant bit).
Incredible read guys...facinating and educational stuff....subscribed!
Can it be done without the double grinder..sure. It's just not as quick.
There are a handful of guys that do it already.
Here is a interesting pic I took yesterday.
It's a Fili, Boker, one of mine and a later production Joseph Roger.
This represents the typical grind on BRW razors (which I consider 1/2 hollow).
Can I (or others) go thinner, sure but it gets a little more delicate...lol
Livi grinds them pretty thin, but his quality control is a slot machine
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