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Scanning Electron Microscope Blade Edge Images

Regarding the long primary grind on the swedish rapiras; I notice my all my rapiras have the same grind except the "ladas" blades I own have the longer grind your swedish rapiras have. I don't know what significance that has though.
 
Has anyone done followup work to this great post? Also, do we know of anyone with access to the sharpness measuring instruments alluded to in this thread?
 
I just started watching the forum and wet shaving about 2 months ago and just discovered this thread. Wow. Great job. I love the data and the objective look at the blades I am hearing so much about. I just happened to be using Personna blades. They come in the blue box in a lot of 100. I hope they are represented in some of the Personna tests here. Its hard to tell since mine don't say "blue" or "red" or "lab" on the box. thanks again for the work

Terry W in Gilbert, Arizona
 
I just started watching the forum and wet shaving about 2 months ago and just discovered this thread. Wow. Great job. I love the data and the objective look at the blades I am hearing so much about. I just happened to be using Personna blades. They come in the blue box in a lot of 100. I hope they are represented in some of the Personna tests here. Its hard to tell since mine don't say "blue" or "red" or "lab" on the box. thanks again for the work

Terry W in Gilbert, Arizona

The blue box are why they are called blue's, the red's come in a red box.
 
...As for the EDS analysis that I post with each new blade, remember that this analysis only looks at the surface of the blade and has no real penetration. The numbers shown would be really rough estimates of what the blade is composed of, but by no means should be considered gospel...

Exactly. Microscopic viewing won't as well tell you anything about the "golden" ingredient in the mix: the sputtering. ;)
 
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Great pictures.
Several observations.
1.No iridium in Polsilver coating.
2.Gillette seven o’clock stainless, the edge looks very jagged.
3.Lord blades are extremely contaminated during manufacturing.
4. Personna lab looks better compared to med prep
 
I don't know if anyone asked this but is there a way to view them from the side? To compare how sharp they are or see the angles to the edge? I love this stuff. Its fascinating.
 
Adding some just completed analysis, based on economics, of the above SEM scan data from @Evilblue so everything is in one place. Conclusion is that for trace elements, like platinum, it's likely that we can rely on the SEM analysis to confirm that some of the element is present thought the percentages by weight may not be reliable. Also, the amounts of some trace elements in blade coatings are likely well below the sensitivity of the SEM so we can't use the results to conclusively determine if something is missing that should be there.

The analysis is as follows:

Per the original SEM analysis poster @Evil4blue the SEM is accurate to +/- 0.5% in analyzing the composition of a blade. Blade weight is roughly a half a gram each so 100 blades weigh 50 grams. 0.5% of that would be a half a gram of platinum that is improbable since platinum currently sells for around $32 U.S. per gram (it sold for more in 2014). To hit the SEM sensitivity threshold a manufacturer would need to apply $16 worth of platinum which is unlikely for 100 blades that are often sold for under $10.

Let's say to sell 100 blades profitably a manufacturer likely needs to keep the amount of platinum applied at less than a dollars worth given all the other manufacturing costs. Even $2 worth of platinum, 0.0625 of a gram (6 one hundredths) would only be 0.125% by weight of 100 DE razor blades that weigh roughly 50 grams. This is well below the SEM sensitivity threshold of +/- 0.5% and may not be picked up. This is also consistent with related patent applications that indicate a coating that is just a few molecules thick.

Based on this the SEM results that show 2.31% of platinum in the Astra SP blades (and similar levels in other blades) by weight do not make any sense. 2.31% of 50 grams in a 100 blade package is 1.15 grams or about $37 of platinum at current prices. This is unlikely to be true for a package of 100 blades that is typically sold for $8-$9. Additionally the SEM showed no platinum in Derby blades that are advertised to have platinum in their coating. The platinum may be there but at too low a level to register.

A reasonable interpretation is that the Astra SPs scanned in 2014 have some platinum, otherwise the SEM would not register it, we just don't know how much. In fact given how little platinum can be economically applied it's impressive that it was picked up at all on the Astra blades. At the low application rates for platinum coatings we likely can use the SEM analysis to confirm something is there but not conclusively show it is absent.

Bottom line the SEM analysis from @Evilblue was excellent work that still provides a lot of information on our blades. Well worth reading for newer B&B members who have not seen it before. Would be excellent if it could be updated an analysis of the latest production blades.
 

lasta

Blade Biter
Adding some just completed analysis, based on economics, of the above SEM scan data from @Evilblue so everything is in one place. Conclusion is that for trace elements, like platinum, it's likely that we can rely on the SEM analysis to confirm that some of the element is present thought the percentages by weight may not be reliable. Also, the amounts of some trace elements in blade coatings are likely well below the sensitivity of the SEM so we can't use the results to conclusively determine if something is missing that should be there.

The analysis is as follows:

Per the original SEM analysis poster @Evil4blue the SEM is accurate to +/- 0.5% in analyzing the composition of a blade. Blade weight is roughly a half a gram each so 100 blades weigh 50 grams. 0.5% of that would be a half a gram of platinum that is improbable since platinum currently sells for around $32 U.S. per gram (it sold for more in 2014). To hit the SEM sensitivity threshold a manufacturer would need to apply $16 worth of platinum which is unlikely for 100 blades that are often sold for under $10.

Let's say to sell 100 blades profitably a manufacturer likely needs to keep the amount of platinum applied at less than a dollars worth given all the other manufacturing costs. Even $2 worth of platinum, 0.0625 of a gram (6 one hundredths) would only be 0.125% by weight of 100 DE razor blades that weigh roughly 50 grams. This is well below the SEM sensitivity threshold of +/- 0.5% and may not be picked up. This is also consistent with related patent applications that indicate a coating that is just a few molecules thick.

Based on this the SEM results that show 2.31% of platinum in the Astra SP blades (and similar levels in other blades) by weight do not make any sense. 2.31% of 50 grams in a 100 blade package is 1.15 grams or about $37 of platinum at current prices. This is unlikely to be true for a package of 100 blades that is typically sold for $8-$9. Additionally the SEM showed no platinum in Derby blades that are advertised to have platinum in their coating. The platinum may be there but at too low a level to register.

A reasonable interpretation is that the Astra SPs scanned in 2014 have some platinum, otherwise the SEM would not register it, we just don't know how much. In fact given how little platinum can be economically applied it's impressive that it was picked up at all on the Astra blades. At the low application rates for platinum coatings we likely can use the SEM analysis to confirm something is there but not conclusively show it is absent.

Bottom line the SEM analysis from @Evilblue was excellent work that still provides a lot of information on our blades. Well worth reading for newer B&B members who have not seen it before. Would be excellent if it could be updated an analysis of the latest production blades.
I think he mentioned in one of the earlier posts that the % composition is only representative of a specific measured area just around the apex, not platinum as 2.31% of the entire blade by weight.
 
The analysis is as follows:

Per the original SEM analysis poster @Evil4blue the SEM is accurate to +/- 0.5% in analyzing the composition of a blade. Blade weight is roughly a half a gram each so 100 blades weigh 50 grams. 0.5% of that would be a half a gram of platinum that is improbable since platinum currently sells for around $32 U.S. per gram (it sold for more in 2014). To hit the SEM sensitivity threshold a manufacturer would need to apply $16 worth of platinum which is unlikely for 100 blades that are often sold for under $10...
In my opinion your analysis is terribly flawed. It could be that your knowledge of SEM and EDS technology is limited. WT% for Platinum does not mean that 0.5% of the blade is Platinum. Platinum, if applied as coating, is deposited on the edge only.
 
I think he mentioned in one of the earlier posts that the % composition is only representative of a specific measured area just around the apex, not platinum as 2.31% of the entire blade by weight.
The composition analysis was based on the entire imaged area in his scans. He noted that he was relying on homogeneity of the entire blades composition for analysis accuracy. You are right that if the areas scanned had a different composition (e.g. only the edge of the blade was coated) then the composition would not represent the entire blade. That said his scans did go well beyond the edges of the blades in many cases.
 
In my opinion your analysis is terribly flawed. It could be that your knowledge of SEM and EDS technology is limited. WT% for Platinum does not mean that 0.5% of the blade is Platinum. Platinum, if applied as coating, is deposited on the edge only.
Actually the economic analysis is confirming exactly that or something similar since the coating is just applied to the surface. It's confirming that the total amount of platinum in a blade has to be a tiny fraction of the 2.3% weight percent indicated by the SEM analysis for the area scanned. @Evil4blue acknowledged in his posts (see link below) that the analysis was counting on blade composition homogeneity.

You are right and we agree that this is unlikely. My analysis is saying that the amount of platinum in a blade has to be less than 0.125% to make any kind of economic sense. In all likelihood it's well below that figure as I doubt there is anything close to $2 worth of platinum in a 100 pack of blades.

 
Actually the economic analysis is confirming exactly that or something similar since the coating is just applied to the surface. It's confirming that the total amount of platinum in a blade has to be a tiny fraction of the 2.3% weight percent indicated by the SEM analysis for the area scanned. @Evil4blue acknowledged in his posts (see link below) that the analysis was counting on blade composition homogeneity.

You are right and we agree that this is unlikely. My analysis is saying that the amount of platinum in a blade has to be less than 0.125% to make any kind of economic sense. In all likelihood it's well below that figure as I doubt there is anything close to $2 worth of platinum in a 100 pack of blades.

So what if we accept your thesis, but say that the SEM is picking up the area of the blade as being solid platinum? Is it able to detect that the coating is only one atom thick or is it considering a larger volume than is actually on the apex? This seems possible, but I don't feel like going and reading how the SEM works again. The atom thick layer would be on either side of the apex, encapsulating it so it seems possible because these aren't the images from another site where he cut the blades in half before scanning.
 
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