Yes, I saw your reply after I posted mine. We are of the same mind set. I just tried to keep it short and sweet. Sometimes I tend to rattle on and on.See Post #16
Yes, I saw your reply after I posted mine. We are of the same mind set. I just tried to keep it short and sweet. Sometimes I tend to rattle on and on.See Post #16
Yes, I saw your reply after I posted mine. We are of the same mind set. I just tried to keep it short and sweet. Sometimes I tend to rattle on and on.
See Al's post #16, and particularly paragraph F quoted below.Now I'm left scratching my head... The silver Star is circa as good as a 7oc yellow in my piccolo, but their thickness turns out to be quite different.
So possibly thickness isn't the reason... Not in a fatip, anyway. Go figure..
F) Normal thickness tolerancing under this standard, for a strip width of <125mm, and from 0.1mm thick, up to but not including 0.15mm, is +/-0.01mm. This means that coiled strip ordered at 0.1mm, can be anywhere between 0.11/0.09mm.
My guess is that the tolerances for modern razor blade steel well exceeds generic ISO standards. Gillette alone has probably spent tens of millions of dollars just tweaking the metallurgy over the years. I'm guessing that any old roll out of the mill isn't up to snuff. A modern razor blade is about the sharpest thing on the planet with cutting edge thickness measured in nanometers! Just my 2 cents.
Businesses don't like making things more expensive just for the sake of it, so there would have to be something critical in the process to warrant the increased cost, and I can't think of any rational justification. It would surely be far easier and cheaper to ensure the processes can accomodate the fluctuations.
My guess is that the tolerances for modern razor blade steel well exceeds generic ISO standards. Gillette alone has probably spent tens of millions of dollars just tweaking the metallurgy over the years. I'm guessing that any old roll out of the mill isn't up to snuff. A modern razor blade is about the sharpest thing on the planet with cutting edge thickness measured in nanometers! Just my 2 cents.
I'm just speculating, and I don't have any evidence to back up my supposition I'll give you that.
From a consumer standpoint though, I will say that I happily pay $25 for 100 feathers, but you couldn't pay me to shave with Treets. Most folks on the board have favorites that they'll pay a premium for. I can tell the difference, and the metallurgy has a lot to do with it. My guess is that one steel mill in 1000 is capable of producing steel good enough to supply the higher end DE blade manufacturers. When PPI in St. Petersburg puts out an RFP for blade steel, I bet it goes out to fewer than 10 suppliers globally. My gut tells me that once you start coating blade edges with platinum, the ISO standards for generic cold rolled steel have probably long since left the building.
Well I just took a look at the measured differences (@Esox compared to @ShavingByTheNumbers) and I get what you guys are saying. They're unbelievably close! The 7'Oclock Super is obviously the outlier. Hard to imagine anybody is controlling thickness by much better than .002mm! Never mind my comments above, I thought we were talking about much larger variations somehow. I'm a bit slow sometimes...
You're welcome everyone. It was an interesting way to spend an afternoon.
As far as manufacturing tolerances go, as Al has said the steel stock is held to ISO 9445 standards. How accurate that is I have no idea but assume it accurate enough given their tolerance levels.
Article: Tolerances to ISO 9445 for cold rolled narrow and wide strip, plate/sheet and cut lengths
Grant @ShavingByTheNumbers no offense taken buddy . Criticism and questioning leads to accuracy in this arena.
We didnt wipe the blades. 36 different types of blades and measuring some for full tucks, combined with liberal use of Bud Light we both felt would increase the odds of drawing blood substantially lol.
He started measuring each blade at 3 points and did so for maybe the first dozen blade types. At each end and in the center on one side of the blade. He found no variance on any blades so he ended up just measuring at the center of the blade between the middle and the edge.
He was most surprised by the fact that he found no variation, at all, between any blades of the same type no matter how many times he measured each one or how many blades of the same type he measured. All were exactly the same and he couldnt find any variance at all.
I was surprised most by the Feather blades. I would have sworn they would be on the thinner side of the spectrum, but clearly they arent. They certainly feel thinner in use. Just playing with them while he was measuring them he was surprised by how different they all felt in relation to spring tension. He suggested a difference in heat treating techniques.
Polsilver which is a favorite of mine, I had assumed a thicker blade, but when it comes to a thickness variation between blades of .0005, I'm not sure anyone would be able to discern it in use. It does however feel thicker in comparison to a Feather.
I'm sticking to my guns on thinking its the coatings that make the most difference. I think it comes down to ones hair type, consistency and composition that dictates which coating will slip through the hair with the least resistance. I've found with GSB, my worst performing blade, to be exceedingly harsh the first shave, but much better the second shave although still harsh. I've never used one for more than two shaves so I dont know if they would smooth out further.
Gillette Black acts in a similar manner, but to a much lesser degree and smooths out considerably with use.
Voskhod. First shave is great, as smooth as any Gillette 7 O'Clock blade. Second and third shaves are very harsh and then they smooth out a lot again.
Several blades I've tried have all change a great deal within the first 4 shaves. As a matter of fact, every blade I've used to 4 shaves and beyond has changed. Some considerably, some less so. Some, like Polsilver, just seem to get better the longer I use them. Gillette Yellow stayed the same to shave #6 I think then went downhill quickly and I tossed it after my 9th shave.
Perma-Sharp Super is another than just got better and was equal in every way to Voskhod, except, it didnt become harsh at any point in over 20 shaves.
The differences in all the blades I have used I put down to coatings. Some like the GSB and Voskhod I believe have a more fragile top coating and my whiskers just tear through it quickly. I think thats why they're so harsh the first shave and substantially smoother the second and its the only way I can explain why so many really like GSB. That top coating doesnt get removed as quickly by passing through their whiskers.
I explained my thoughts on this to him as well and he agreed but remained uncertain. He was happy to keep all blades measured so he can find his best blade in the post war Tech I also gave him.
I'm also sticking to my guns on the simple fact that modern DE blades are too thin. If they were .006" thick, a lot of issues we all have, I believe, would come to a quick end.
Another thing I'm quite curious about, but not sure how to test, is the hardness of blades. All I'm sure are very hard as far as steel goes, but that can also make them brittle, especially being so thin. I've read they cant be tested with an impact tester for RC hardness because they fracture.
In the end its really anyones guess why one blade performs better than another. I'm glad I've tried so many and each of my DE's has their favorite blades.
Thanks, Mike, for getting back on this. It makes sense that you guys didn't wipe off the wax, especially with the Gillette 7 O'Clock Super Stainless. From my experience, that blade has been the toughest one so far to wipe off all of the wax from it. So, it makes sense to me that you guys ended up with a large measurement for that blade. Wax might also be the reason for your larger Shark Super Chrome measurement. Maybe feel with the Mitutoyo micrometer was involved, too, but with wax being on your blades, I'm willing to chalk up our differences to that.
It's interesting that you guys didn't see any variations at all. I've seen variations, although small, on the same blade sample, which is why I take the median of six measurements on each sample, three measurements along each side. Variations in blade thickness from sample to sample also exist, but they are usually small. Blade thickness typically varies from sample to sample by +/- 2 %. ISO standards aren't an issue.
I'm with you about how DE blades should be thicker. There's a real market for that option.
He was careful not to measure of any of the waxed areas, that was taken into account Grant, but as far as the rest of the body of the blade goes, it was as is when unwrapped and measured to the best of his ability.
He did mention on more than one occasion while measuring them that they all measured to the exact thickness he recorded and he was unable, for example, to get the Polsilver, which measured at exactly 0.0040 to get it to measure at anything but exactly that and not say .0039 or .0041 and that was across all 5 blades from the same tuck. This is why he stopped measuring at 3 places. He could find no variation across the width of the blade so he just started measured the center of each blade.
That was also consistent across all samples of the same blades assuming I had more than one blade, which I did not have for many types. If I had a full tuck, each blade of the tuck, or type if I had more than a single blade, was measured.
Each one measured exactly the same as the next of the same blade from the same tuck. He was quite surprised at that consistency from blade to blade, but thats not to say that 100 feet further down the spool of wire they would be exactly the same to .0001" either.
That variation may come from tool wear. A sample from a first run with say a fresh and new polishing wheel may perhaps yield a .0001" difference somewhere along the run of a length of stock, but if it did, it would quite likely be so gradual you'd never notice it unless you measured the first blade from a spool and the last blade from the same spool of stock.
We may have standards for stock materials via ISO tolerances, but it would be a guess at blade manufacturing tolerances.
It all still comes down to this, could someone notice a difference between for example a Polsilver that measured .0039" and one that measured .0041"?
Even if they do vary a few 10 thou thats not nearly enough to justify the difference in feel. What is the cause of that difference in feel and why do the above blades vary so drastically in performance?
I would like to understand that, but I have a feeling I never will.
Thickness is only one factor in razor blade "feel", and is probably much less important that the angle of the grind, the style of the grind (single or double bevel, for instance), and the quality, angle, and width of the actual edge hone. Coatings play a large role in how "slippery" the edge is to the hair as it's cut.
And of course there is manufacturing variation as well.
I'd like for you guys to try again with that blade, after cleaning off the blade and the micrometer's measuring surfaces, because I suspect that wax got in there and caused a larger measurement.
I'll keep that in mind Grant and the next time I go over I'll take one with me and measure again.
I wonder if thats perhaps not a difference from start of spool material to end of spool. Or some other anomaly, but who knows.
Even a .0007" difference I doubt I'd notice and to be completely honest I'm not sure I'd notice a difference of .001" in thickness. All the measuring has really told us absolutely nothing about the inherent stiffness of any given blade, which is what I had hoped for lol.
Would you be able to measure the same sample from before?
You might notice a difference of 0.017 mm. Blade thickness relates to blade rigidity. All steel blades have roughly the same material stiffness, so blade stiffness differences basically come down to geometric differences, primarily thickness differences. A blade that is 0.117 mm thick is about 60 % stiffer than a blade that is 0.1 mm thick. My guess is that you'd notice the difference.