Thin Blades?

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.

The thicker blades (like SE and Injector blades) are much less prone to chatter and digging in so why were they abandoned in favour of the bitey thinner blades?
Of course it saves metal and transport costs but the thicker ones just shave nicer...

And why can't we get nice thick stainless DE blades now?

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

Don't know. Thin blades save on material (the largest cost in manufacturing), but are more difficult to make and harden. As far as smooth cutting goes, I believe that is largely a matter of the design of the razor, so long as the blade is properly supported a thin blade should not cut much differently than a thick one. Caveat there is that a thick blade requires less support due to it's inherent rigidity.

But I don't "know" any of this....

Peter

Certainly razors like torsion slants and Wardonias put a big curve on the thin blades to lend them extra rigidity but the thicker blades are inherently stiffer which, for me at least, makes for a more comfortable shave.

A friend of mine has some German carbon steel blades from the 1940s which are incredibly thin. He has a packet of 50 blades but when he first showed me them I thought it was a fairly standard pack of 10; they must be about the thickness of fine paper. I'd guess the Germans had other uses for steel at that time.

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.The thicker blades (like SE and Injector blades) are much less prone to chatter and digging in so why were they abandoned in favour of the bitey thinner blades?Of course it saves metal and transport costs but the thicker ones just shave nicer...And why can't we get nice thick stainless DE blades now?

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it's like if you go to the Deli And Order a Slice of Cheese, Now if the Merchant can Charge the same Price, ,for a THICK or THIN Slice he is going to be selling Thin Slices , and his Bulk will Yield more Slices. ..

psfred said:

Don't know. Thin blades save on material (the largest cost in manufacturing), but are more difficult to make and harden. As far as smooth cutting goes, I believe that is largely a matter of the design of the razor, so long as the blade is properly supported a thin blade should not cut much differently than a thick one. Caveat there is that a thick blade requires less support due to it's inherent rigidity.

But I don't "know" any of this....

Peter

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I would think the cost of labor, machinery, and factory rent would exceed the cost of material in thinner blade making vs thicker blade making.

In my experience in manufacturing, materials costs swamp everything else. In my current work assignment, we run a several billion dollars a year or so in raw materials through a plant that costs a couple hundred million a year to operate. This is true of any plant that takes something and turns it into something else on a production scale.

Not the same at all as information processing, banking, etc. It's the "value added" part of capitalism, the part we no longer do so much of in global terms.

Think of how many razor blades are produced by PPI and then add up the tonnage of steel needed to make the blades twice as thick.

Peter

So just to follow this discussion up, after shaving with thicker vintage blades their great advantage is the extra rigidity but the carbon steel is a PITA for tugginess and corrosion.

Does anybody make a modern stainless blade that has the extra thickness of those old blades?

mjclark said:

So just to follow this discussion up, after shaving with thicker vintage blades their great advantage is the extra rigidity but the carbon steel is a PITA for tugginess and corrosion.

Does anybody make a modern stainless blade that has the extra thickness of those old blades?

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I don't believe so. I've measured many of the most popular blades and they are all uniformly about .004", which is about .002" slimmer than the carbon steel blades of the old days.

Highspeedlane said:

I don't believe so. I've measured many of the most popular blades and they are all uniformly about .004", which is about .002" slimmer than the carbon steel blades of the old days.

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Based on my measurements, which will make their way into the Comprehensive DE Razor Blade Data Table in the ShaveWiki, I've measured average blade thicknesses from 0.089 mm (0.0035 in.) to 0.102 mm (0.0040 in.). Overall, across all of the blades that I've measured, the current mean and median blade thickness is 0.096 mm (0.0038 in.). So, yes, they are about 0.004 in. thick. Someday, I'd like to measure some vintage blades or find a current blade that is relatively thick compared to other current blades.

ShavingByTheNumbers said:

Based on my measurements, which will make their way into the Comprehensive DE Razor Blade Data Table in the ShaveWiki, I've measured average blade thicknesses from 0.089 mm (0.0035 in.) to 0.102 mm (0.0040 in.). Overall, across all of the blades that I've measured, the current mean and median blade thickness is 0.096 mm (0.0038 in.).

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That sounds about right Grant. Great job you are doing with gathering technical info on today's shaving products.

Highspeedlane said:

That sounds about right Grant. Great job you are doing with gathering technical info on today's shaving products.

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Thanks, Lane! Have you examined the Comprehensive DE Razor Blade Data Table yet?

Maybe it's just a case of we found a way to produce roughly the same product for less. I believe this has been stated though. It could have been another marketing scheme as well.

KeenDogg said:

Maybe it's just a case of we found a way to produce roughly the same product for less. I believe this has been stated though. It could have been another marketing scheme as well.

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If blades were 1.5 times thicker back in the day, and the steel had the same stiffness, then by mechanics of materials, blade deflections of current blades are 3.4 times that of vintage blades for the same blade reveal. Blade flutter, at least, should be more of an issue with current blades than vintage blades. I don't have it yet in the Comprehensive DE Razor Blade Data Table, but in one of my Excel files, I have a column for what I call "Blade Deflection Factor" which relates to 1/T^3.

ShavingByTheNumbers said:

Based on my measurements, which will make their way into the Comprehensive DE Razor Blade Data Table in the ShaveWiki, I've measured average blade thicknesses from 0.089 mm (0.0035 in.) to 0.102 mm (0.0040 in.). Overall, across all of the blades that I've measured, the current mean and median blade thickness is 0.096 mm (0.0038 in.). So, yes, they are about 0.004 in. thick. Someday, I'd like to measure some vintage blades or find a current blade that is relatively thick compared to other current blades.

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Superb project!
Oh, if only someone made a thicker stainless blade think of the shave quality we could get with that!

mjclark said:

Superb project!
Oh, if only someone made a thicker stainless blade think of the shave quality we could get with that!

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Thanks! Yes, I think, too, that thicker blades would generally produce better shaves. However, how much better? I'm guessing that manufacturers found that reducing blade thickness to around 0.1 mm didn't bother much guys. If it did really make a big difference, then guys would have noticed and market forces would have driven some manufacturers to continue producing thicker blades, I think. Maybe I'm wrong about it, but I'm guessing that the difference in shave quality is relatively small.

ShavingByTheNumbers said:

Thanks! Yes, I think, too, that thicker blades would generally produce better shaves. However, how much better? I'm guessing that manufacturers found that reducing blade thickness to around 0.1 mm didn't bother much guys. If it did really make a big difference, then guys would have noticed and market forces would have driven some manufacturers to continue producing thicker blades, I think. Maybe I'm wrong about it, but I'm guessing that the difference in shave quality is relatively small.

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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?

ShavingByTheNumbers said:

If blades were 1.5 times thicker back in the day, and the steel had the same stiffness, then by mechanics of materials, blade deflections of current blades are 3.4 times that of vintage blades for the same blade reveal. Blade flutter, at least, should be more of an issue with current blades than vintage blades. I don't have it yet in the Comprehensive DE Razor Blade Data Table, but in one of my Excel files, I have a column for what I call "Blade Deflection Factor" which relates to 1/T^3.

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I think metal stiffness can vary considerably due to variability in alloy and heat treatment. Compare a tin can with a piece of spring steel of the same thickness. I imagine the blade manufacturers have some control over stiffness.

Saxonbowman said:

I think metal stiffness can vary considerably due to variability in alloy and heat treatment. Compare a tin can with a piece of spring steel of the same thickness. I imagine the blade manufacturers have some control over stiffness.

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As far as I know from a material properties table in one of my mechanics books, the yield and ultimate strength of different steels can vary quite a lot, but not the modulus of elasticity, which is fairly consistent, and it is modulus of elasticity that factors into small blade deflections during shaves. I have to bend the blades when I clean them before measuring them, and I don't notice any difference in how hard it is to bend the blades, so that is my empirical evidence that current blades have very similar elastic moduli, which fits with the material properties table regarding very similar elastic moduli across different steels. Vintage steel blades should have similar elastic moduli as modern steel blades, but thicker steel of the vintage blades results in more stiffness. (Regarding a tin can versus a piece of spring steel, even if you knew that the thicknesses were the same, and even if you knew that the materials were the same, the stiffnesses would be different because of different geometry.)