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A little closer look at Gillette 7 O'Clock blades (SEM Comparison)

In this post we're going to look at the Black, Yellow, and Green 7 O'clock blades plus a Gillette Silver Blue.

Here's all the blades uncleaned, straight from the wrapper:

Gillette Black:



Gillette Yellow:



Gillette Green:



Gillette Silver Blue:



Next, I washed all the blades in high grade IPA in a sonicating bath. Here's what they look like now:

Black (left) - Yellow (right):






Black:




Yellow:



Silver Blue (left) - Green (right):







Next I mounted all the blades on edge and took some photos of the cutting edge:

Black:







Yellow:







Green:







Silver Blue:







Lastly, I'm attaching the alloy analysis:

Black:



Yellow:



Green:



Silver Blue:




So have we learned anything? First, the 7 O'clock series seems to be a thinner blade than some of the other blades I've looked at. they measured about 10um thinner than a Voskhod or Personna Lab/Med blade. I would imagine that in a razor that allows a blade to flex or flutter, you'd want to avoid really thin blades, but this is my opinion and I have no empirical evidence that this really affects someone's shave.

Next, it appears that the platinum coatings on the Black and Silver Blue blades really make the blades look crappy (scientific term:biggrin1:) under magnification. Both the Yellow and Green blades look much cleaner at high mag. But we now know that when Gillette adds Platinum to the name of a blade, they really add platinum to the mix. Not every company appears to do that.

As I think of stuff I will update this thread.

Enjoy!
 
Excellent selection for comparison and much appreciated esp the highly magnified side view of edges which looks as though the Blacks to be the most even edge.
 
Since they are identified as the Gillette Super Stainless, I am assuming they are manufactured in Russia. The Gillette Green blades manufactured in India are labelled PermaSharp.
 
Someone tell me in layman's terms what those pictures mean.
These are nothing more that photos of different blades using a special kind of microscope. This microscope allows me to magnify the razor's edge, both profile and on-edge, way more than a conventional (optical) microscope.

The graph with the peaks at the bottom of the post is an elemental analysis of each blade and allows us to get a general idea of the composition of the alloy used to build the razor.
 
I can't get enough of these microscope comparison threads. And I learned something new today; Yellows are not coated. I always thought they were coated for some reason.
 
I can't get enough of these microscope comparison threads. And I learned something new today; Yellows are not coated. I always thought they were coated for some reason.
All these blades have a antifriction coating, the Yellows and Greens don't include platinum in the formulation.

If you look at the side profiles of all the blades, you'll notice that the grinding marks seem to disappear as you get closer to the edge, that smooth look is from the polymer coating. Go look in the Voskhod/Feather thread and I posted some images of used blades, you can see that the poly coating is gone after some use.
 
Many thanks for the time and effort that you put into this. I very much enjoy the thread as well as having learned a thing or two, or...
 
I can't get enough of these microscope comparison threads. And I learned something new today; Yellows are not coated. I always thought they were coated for some reason.
Just curious, how did you get to this conclusion?
I ask because I believe you are very wrong.
 
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