DE blade sharpness

Discussion in 'Safety Razors' started by Rusty blade, Jul 11, 2019.

  1. Rusty blade

    Rusty blade The Good Humor Man

    I'm going out on a limb here, but I think most razor blades are sharp. What seems to separate them in terms of perceived sharpness when shaving is the thickness or stiffness of the blade. Example: most would say Derbys are not sharp and Feathers are sharp. But if you look at the stiffness of the blades the Derby is quite thin and flexible and the Feather is quite stiff. If you put a Derby in a shavette or SE razor you will see it is stiffened by the blade holder and it makes them very sharp. And most SE blades are very thick and stiff and thus very sharp when shaving. Anyone care to comment?
     
    Last edited: Jul 12, 2019
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  2. Hembree

    Hembree Not as pretty smelling

    Interesting thoughts.
     
  3. RyX

    RyX DoH! Staff Member

    Moderator
    Not a scientific test, but I've noticed Kai blades are also stiff. Not any thicker that I can tell from "feeling" the thickness. They flex different from other blades and have much the reputation for sharpness shared by Feathers.

    We need a metallurgist to chime in and share wisdom about tempering?
     
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  4. Edison Carter

    Edison Carter Goo-bloomin' Stankster

    I think all modern blades are. 004" or very close.

    I've noticed differences in flexibility as well as ease of snapping in half.

    I have a shaving tool using 1/2 DE blades. The mechanism does not flex the blade. My opinion is that Feathers were sharper in that tool, DE tools, and a shavette when compared to other blades including Derby.

    Perhaps the particular steel used is a factor.
     
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  5. stingraysrock

    stingraysrock PIF'd away his custom title

    I am the fleet manager, among other things, for a large furniture retailer in the southeast. I know for sure that as tires wear, they last longer than you would think.

    At first, when tires are new, they have taller tread depth, and therefore when you turn a corner, there is more material on the tire that scrubs off. As the tires wear down, there is less scrub, and so the tires, while they are still being worn down, they get stiffer. Almost like as whiskers feel more coarse when they are short, versus softer when they get longer.

    Feather's do seem sharper to me, but I agree with your assessment that flexibility may result in a difference in the feeling of sharpness.
     
  6. Terry

    Terry Well-Known Member

    If the blade pulls or tugs my whiskers, its dull. If the blade doesn't pull or tug my whiskers, it's sharp enough to use.
    Sometimes the razor head helps with the shave. I know that most more experienced shavers say nay to that, but I have found the more efficient razors help the removal of the whiskers. The type I like are Feather, Kai, Personna Gem, B-20 and the like. Not scientific, but MY face and head tells ME what to use.
    If you are interested, there was a nice article on it here. I found it interesting anyway.

    https://sharpologist.com/2019/07/the-science-of-blade-sharpness.html


    tp
     
  7. RyX

    RyX DoH! Staff Member

    Moderator
    Thank you for linking that Terry! I'd read it before, but couldn't find it. Closest to a scientific study I've seen. The testing and first, second, & third use data takes much mystery out of the subject.

    Tapatalk Spam Tag
     
  8. BigMike

    BigMike Well-Known Member

    As @RyX said, Kais are very stiff. And I feel they are pretty sharp.
    As for Feathers, they are the most likely to cut my skin and the least able to cut my wiskers. I don't know how to explain it, but Feather is one of the few blades I don't like: it just won't cut. Wierd, huh?
    IMO, Bic chrome platinum is the sharpest. Too harsh for me, but a good blade.
     
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  9. Rusty blade

    Rusty blade The Good Humor Man

    There is no doubt that edge quality and coatings of various sorts does make a difference in terms of smoothness and longevity. But if you consider initial sharpness of a blade on a first shave they are all pretty much the same, perhaps with a few exceptions. From all the blades I have tried blade thickness seems to make the biggest difference. I also notice that the stiffer blades seems to lose their edge/sharpness quicker than a more flexible blade. If I had the energy or set up I would do some kind of test to see if this theory holds water. And yes, I know...blades are one of those YMMV things.
     
    Last edited: Jul 12, 2019
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  10. Edison Carter

    Edison Carter Goo-bloomin' Stankster

    Take a set of calipers or even an old fashioned micrometer an I think you will find thicknesses to be within a few ten thousandths of .004". I had similar wondering and measured everything I had at .0038"- .004".

    Here is some interesting data to review.

    https://www.refinedshave.com/razor-blade-sharpness-summary/
     
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  11. jmudrick

    jmudrick Well-Known Member

    Based on the data sets published on the forums there is no apparent relationship between thickness and performance.(sharpness, smoothness, longevity).

    Sent from my Pixel 2 using Tapatalk

    These are from Mike/Esox as posted on B&B forum.

    https://drive.google.com/file/d/11hRl4dmAhgrQtuWJM5pTR1onmUxvwv89/view?usp=drivesdk
     
    Last edited: Jul 12, 2019
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  12. RyX

    RyX DoH! Staff Member

    Moderator
    I don't know if TSD ever had a forum specifically for discussion of replaceable blades. Others may, but the YMMV nature has enough variation I'd add that Your Opinion May Vary (YOMV) happens even for an individual. Especially when a Newbie tries the same blades a year later. It's an illustration of how the blades remain the same but the technique of the User improves and somewhat levels the performance of blades.

    Thanks to everyone bringing the evaluations from other sources! Information is power and there is wisdom to be gained.
     
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  13. RyX

    RyX DoH! Staff Member

    Moderator
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  14. brit

    brit Well-Known Member

  15. RyX

    RyX DoH! Staff Member

    Moderator
    Thank you Gary @brit! Through your contribution and others we are gathering the Good Stuff.
    :eatdrink047:
     
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  16. brit

    brit Well-Known Member

    :eatdrink047:. found on the web..cheers..pretty cool site..
     
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  17. Rusty blade

    Rusty blade The Good Humor Man

    I think, for me, when I read these blade reviews, there are no standard definitions for sharpness, longevity, smoothness, edge-iness etc.
     
  18. jmudrick

    jmudrick Well-Known Member

    Here you go.

    in thickxxmm thickxxBLADE
    0.00450” 0.114mm Gillette Nacet Stainless
    0.00450” 0.114mm Shaverboy Super Stainless

    0.00425” 0.108mm Gillette 7 O'Clock Super Stainless (0.089mm*)
    0.00425” 0.108mm Lord Platinum

    0.00410” 0.104mm Feather

    0.00400” 0.102mm Astra Superior Stainless
    0.00400” 0.102mm BIC Chrome Platinum
    0.00400” 0.102mm Croma Diamant Stainless
    0.00400” 0.102mm Derby Extra (pre 2016, current blade 0.089mm*)
    0.00400” 0.102mm Gillette Sword
    0.00400” 0.102mm Kai*
    0.00400” 0.102mm Personna Med Prep
    0.00400” 0.102mm Personna Platinum Chrome (Personna Red)
    0.00400” 0.102mm Polsilver SI
    0.00400” 0.102mm Rapira Platinum Lux
    0.00400” 0.102mm Sharp Star
    0.00400” 0.102mm Super Max Blue Diamond
    0.00400” 0.102mm Super Max Platinum
    0.00400” 0.102mm Voskhod

    0.00390” 0.099mm Bolzano Superinox
    0.00390” 0.099mm Shark Super Chrome
    0.00390” 0.099mm Treet Platinum Super Stainless

    0.00375” 0.095mm Gillette New Improved Stainless
    0.00375” 0.095mm Gillette Platinum
    0.00375” 0.095mm Gillette Rubie Platinum Plus
    0.00375” 0.095mm Trig Silver Edge
    0.00375” 0.095mm Vidyut Super-Max
    0.00375” 0.095mm Wizamet Super Iridium Extra Stainless
    0.00375” 0.095mm Zorrik Super Platinum

    0.00350” 0.089mm Astra Superior Platinum
    0.00350” 0.089mm Gillette 7 O’Clock Sharp Edge
    0.00350” 0.089mm Gillette 7 O’Clock Super Platinum
    0.00350” 0.089mm Gillette Silver Blue
    0.00350” 0.089mm Perma Sharp Stainless
    0.00350” 0.089mm Sputnik
    0.00350” 0.089mm Treet Platinum
    0.00350” 0.089mm Wizamet Super Iridium

    Sent from my Pixel 2 using Tapatalk
     
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  19. rbilly

    rbilly Well-Known Member

    I worked for a company that makes surgery robots, and they could test blade sharpness to some extent. With that said I'm not sure for instance sharpness defines how well a blade works for each individual. One example, I brought in 10 of each blade 10 different brands, out of the ten the famed feather was not the sharpest, my thought was that the Nacet would take the title becauae they have always felt the sharpest. But the one blade that took the crown was a blade I really never considered to be on the sharper side of the spectrum and it's a blade I dislike and that was the bic chrome platinum blade. Gillette 7 0 clock yellow, nacets, feathers, and one other I forget off the top all ranked close, so much so that the engineer who does laser honing stated it's so close there wouldn't be much of a difference, but the other factors would make each blade stand out. Stuff like what it's coated with, how the steel is produced, overall stiffness of the blade. He also said when mass producing cutting edges with grinding wheels, a blade made the day after the machines are tuned up will perform better then blades produced 9 months after the tune up.
     
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  20. jmudrick

    jmudrick Well-Known Member

    I wonder if that explains the rather high percentage of bad blades we seem to find with the BIC chromium. I love the blade, it is indeed sharp, but a number have gone straight in the bin.
     
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