blade sharpness and width

[Mink]

I just had a wonderful shave with a Merkur blade, although I did have just a little bit of burn. When I went to take the razor apart for cleaning (EJ 89L), I noticed that the blade seemed to be wider - sticking further out from the head of the razor. If a blade is wider, and more of the edge is digging further into your skin for the same stroke with a narrower blade, couldn't that give the sensation of the blade being a more aggressive, sharper edge?

So, I got out my calipers and measured the width of several from each box of 7 blade manufacturers. The difference isn't great, but there is a difference. If you think about cutting .004in (0.1mm) deeper into your skin, that could be a lot of skin to hurt. Also, figuring the average hair to be about that same thickness to about 50% more (I'm sure it's much more for some - but stay with me) the less supported blade edge would stay with the whisker longer resulting in either a cleaner cut - or pulling (if dull). The widths between blades in a box are within .001in, or less. But it was very interesting to see that the sharper blades (member comments) are wider than the more comfortable blades.

blade/width:

Merkur/.872in
Gillette 7-Yellows/.868
Feather/.867

Crystal/.865
Derby/.864 (I wonder if the variance in blades is due to a variance in width)

Shark/.861
Red IP/.858

For me, not getting razor burn with the Feather and Merkur is a challenge. My most comfortable shaves have been with a Shark. I'd be curious what the widths are on other blades (Iridiums, Gillette Blacks, Kai, etc). Anyway, something to consider in the grand quest for the perfect shave.

 

[JPM]

Interesting info. I would never have thought to measure the blades.

 

[Sailorman]

I may be wrong, but I would thing that slight variations in widths between blades would be compensated for by the angle you need to hold the razor. If a blade is 0.004 wider than another blade, you wouldn't just jam it just that much further into your face. Woud you?

My guess is that a narrow blade might call for a smaller angle of attack, all else being equal, than a wider blade. That might make for a more comfortable cut as the blade edge would be more perpendicular to the hair shaft. But I'm not sure how much 0.1 mm would make. My trig skills are pretty rusty nowadays. But then, you'd have to account for the distance between the edge of the cap and the edge of the safety bar/comb as well as the chord of the curve of the cap. I guess that's why the same blade performs differently in different razors, even if the razors have the same gap.