Thin Blades?

mjclark said:

There's no doubt that the thinner blades have more tendency to bite and dig in.
This is especially noticeable in shavettes where a shave with a thick Injector blade is a lot more comfortable than a half-DE blade and with the thicker GEM SE blades.

The curvature in the cap of DEs can brace the thin blade and lend it rigidity, especially with those torsion slants.

I'd happily pay a bit more for a pack of thicker stainless blades just to find out...

...And what would happen if you doubled the thickness of the blade by dropping two thin blades into a DE, one on top of the other?

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Thanks for sharing your experience. I'm only a DE shaver so I can't relate, but I believe you. I agree that thicker blades would be nice to try. There's probably a market for it. Blade prices vary a lot, and some popular blades are more expensive, so why can't they take a good lesser expensive blade, make it thicker, and bump up the price accordingly while still being less expensive than a lot of other blades?

I think thin Blades were started in the depression as a way to price differentiate the person willing to buy more expensive blades from the person who would not. It helped major producers keep more of the market in a way that was still profitable, even if there was little or no cost savings in the production. It kept the premium buyer paying more, and the non-premium buyer buying name brand.


From one of the prior threads on Thin Blades. They were defined to be of a certain thickness by the U.S. Government for at least part of their history:


Although I would agree that thin blades were mainly about the marketing, and were sold as the lowest cost blade by Gillette, I did find that the United States Code of Federal Regulation defined Thin blades as .004 inches thick or less, and that it was an unfair trade practice to call a blade a thin if it was thicker than that. https://books.google.com/books?id=5h...blades&f=false

Thins were also made by Schick in the early 60s before stainless during the short time they made Krona, non-stainless blades. I see others made thin blades in the pre-stainless era as well. Note their low pricing as well. https://books.google.com/books?id=u4...0thins&f=false

Very interesting! Thanks, [MENTION=5974]haiti222[/MENTION].

Over in another thread there's a suggestion that, for some reason, the Kai DE blades are stiffer than most modern blades giving the same effect as if they were thicker.

This definitely requires further investigation.

mjclark said:

So the thinner more flexible DE blades started appearing in the 1930's and that's the blade we're all used to in stainless form now.

But why the change from the thicker blades - the change in cutout patterns was due to patent design competition.

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BSAGuy said:

The thin blades are just so cheap to produce and no one (but us) knows better.

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I'm just now reading a history of the Gillette Safety Razor Company, and @BSAGuy is correct on the origin of the Thin Blade. In 1938, Gillette came out with the new Thin Blade as a cheaper (but still Gillette) alternative to the Blue Blade, which continued to be produced. At the time, Gillette's major competition in blades was on price: Other manufacturers were selling cheaper blades, cutting into Gillette's market share and profits. Gillette had already come out with some "white label" blades that were produced by Gillette but didn't meet the quality standards of the Gillette-branded blades. But some people wanted Gillette blades. They just wanted a cheaper Gillette blade. So Gillette began producing the Thin Blade. The two blade types (Thin and Blue) were sold by Gillette through the 40's and 50's at different price points.

mjclark said:

Over in another thread there's a suggestion that, for some reason, the Kai DE blades are stiffer than most modern blades giving the same effect as if they were thicker.

This definitely requires further investigation.

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I'm going to measure more in the future, but right now, I've only measured one Kai blade. The thickness was 0.100 mm. That's on the thicker side of average, but it's normal and not the thickest blade out there. As I mentioned earlier in this thread, the elastic modulus is fairly consistent across different steels, so with basically the same geometry, steel blades should basically have the same stiffness. Kai blades shouldn't feel any stiffer than other 0.1 mm thick blades. I'd have to bend them side by side to see if I could tell any difference, which shouldn't be noticeable.

I used thins and blues in the '60s. I remember getting one shave from a thin and three from a Blue Blade. That was then. Stainless blades lasted longer of course.

I never measured, but i have the feeling that BIC blades are thiker then the average, and the true is they have a diferent beaviour, some love them, some hate them. They are very popular here in Portugal, and widely available.

manuel said:

I never measured, but i have the feeling that BIC blades are thiker then the average, and the true is they have a diferent beaviour, some love them, some hate them. They are very popular here in Portugal, and widely available.

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I've only measured one BIC Chrome Platinum blade so far. It had a thickness of 0.100 mm, which is thicker than average, but still within the normal range of thickness values.

ShavingByTheNumbers said:

I've only measured one BIC Chrome Platinum blade so far. It had a thickness of 0.100 mm, which is thicker than average, but still within the normal range of thickness values.

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You wouldn't happen to have a list of the various blades that you've measured and their thickness, would you? That'd be pretty interesting.

ShavingByTheNumbers said:

I've only measured one BIC Chrome Platinum blade so far. It had a thickness of 0.100 mm, which is thicker than average, but still within the normal range of thickness values.

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I was exactly talking about those ones, the Chrome Platinium. Maybe they just stiffer, then why i though they are thiker.

Komboloi said:

You wouldn't happen to have a list of the various blades that you've measured and their thickness, would you? That'd be pretty interesting.

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I have all of my measurements in an Excel file. As I measure enough samples to confidently report average measurements, they will go in the Comprehensive DE Razor Blade Data Table (already started) and the DE Razor Blade Dimensions Table (not started yet) in the ShaveWiki and supporting documentation with blade sample measurements will go in the individual blade pages. The collection of user ratings will roughly follow the same schedule as blade measurements. I'd rather not report preliminary results, but anything I type here will eventually be superceded. I'm okay reporting preliminary blade thicknesses. Here you go:

Though not an engineer, I find this fascinating, and I'm grateful for the work and research being done. However, nurse that I am, I think I could use some Tylenol now. JK

manuel said:

I was exactly talking about those ones, the Chrome Platinium. Maybe they just stiffer, then why i though they are thiker.

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Blades have roughly the same elastic modulus and geometry, so blades vary in stiffness largely due to thickness variations. A blade with a thickness of 0.1 mm will require about 37 % more (bending moment) force to bend it than a blade with a thickness of 0.09 mm. When I bend various blades during the cleaning process before measuring them, I haven't noticed any difference from day to day, but I wasn't looking for it. I'm sure that if I take blades with a known 0.1 mm thickness and compare them to blades with a known 0.09 mm thickness that I'll notice the difference, but otherwise, it doesn't stick out and hit me in the face.

Graybeard57 said:

Though not an engineer, I find this fascinating, and I'm grateful for the work and research being done. However, nurse that I am, I think I could use some Tylenol now. JK

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I agree that this thread is becoming more and more interesting with some excellent science and engineering input.

So are the Kais and the Bic Chromes definitely thicker, albeit by 0.01mm, or are there some other factors at work here too?

ShavingByTheNumbers said:

Blades have roughly the same elastic modulus and geometry, so blades vary in stiffness largely due to thickness variations. A blade with a thickness of 0.1 mm will require about 37 % more (bending moment) force to bend it than a blade with a thickness of 0.09 mm. When I bend various blades during the cleaning process before measuring them, I haven't noticed any difference from day to day, but I wasn't looking for it. I'm sure that if I take blades with a known 0.1 mm thickness and compare them to blades with a known 0.09 mm thickness that I'll notice the difference, but otherwise, it doesn't stick out and hit me in the face.

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That's some great stuff. I'm not sure I understand it all, but I think I get the gist. Thanks!

When Gaisman developed the Probak blade in the late '20's one of his selling points was that the blade wasn't of uniform thickness. I think it was thinner in the middle with the idea being that it would flex more to better "fit" the razor but still be thick enough at the edges for keenness. Would that vary the "elastic modulus" and "bending moment"?

[MENTION=111161]ShavingByTheNumbers[/MENTION]: Do you have (or want) some vintage blades to provide a comparison? Like the Gillette green blades or Gillette Blue Blades?

mjclark said:

I agree that this thread is becoming more and more interesting with some excellent science and engineering input.

So are the Kais and the Bic Chromes definitely thicker, albeit by 0.01mm, or are there some other factors at work here too?

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I haven't measured more than one of each blade, but unless the manufacturers have changed their steels, the blades are really around 0.100 mm thick, as measured with my digital caliper having a resolution of 0.001 mm. Again, there are no confidently calculated averages yet using enough blade samples, but blade thickness varies little unless the manufacturer changes the steel.

ShavingByTheNumbers said:

I haven't measured more than one of each blade, but unless the manufacturers have changed their steels, the blades are really around 0.100 mm thick, as measured with my digital caliper having a resolution of 0.001 mm. Again, there are no confidently calculated averages yet using enough blade samples, but blade thickness varies little unless the manufacturer changes the steel.

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Thanks!
So I wonder why there are reports of the Kais being stiffer.

This was prompted by somebody recommending the Kais for the 2011 R41 because this was the only blade that seemed to eliminate chatter in that razor.