How Are Commercial Razors Sharpened?

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SeattleB

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Gillette and Schick sharpen miles of blades every day. What are their techniques and what can we learn from them? I would think that their goals are to reach the target sharpness as quickly as possible and while consuming the least amount of abrasives. A few of my questions:
  • Do they raise a burr? How big?
  • How do they deburr?
  • I wouldn't expect them to have a human visually inspecting for a burr, or visually inspecting to confirm it was removed. What do they do?
  • In the sharpening process, how much material do they take off the edge, i.e., how much is the blade shortened?
  • What is their stone or grit progression?
  • Do they strop? With what material and compound?
 

KingShapton

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Perhaps a shaving forum would be more suitable for this question ....?!

And I personally don't think that anything can be learned here from an industrial, fully automated manufacturing process for mass-produced goods for our interests.
 

inferno

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i would imagine razors coming as rolls of like a 1 kilometer. 25mm wide. you start unrolling the roll and it goes into a furnace where it gets HT'ed. then it goes into another chamber where they quench it. then another chamber on teh same line where they temper it.

and then its probably goes trough a 2 stage sharpening with most likely wheels or belts.

then i gets chopped into pieces.

thats how i would do it at least. just one long continous process.
 

inferno

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remember this is mass production. and then you need to produce in mass.
 

kayman67

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Very.
But as far as knives go, I had countless encounters with huge burrs on mass produced blades, enough to consider that there was no deburr stage whatsoever.
 

inferno

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moras are truly mass produced. and none of those ever had a burr. not 20 years ago and not now. never ever happened.
and these are truly mass produced.
 

SeattleB

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I personally don't think that anything can be learned here from an industrial, fully automated manufacturing process for mass-produced goods for our interests.

I thought we could learn how to sharpen efficiently and remove the least amount of metal. Far more than knife makers, a razor company has the challenge of a high ratio of cost of sharpening to the cost of the product.

Wouldn't it be great to sharpen in less time? To sharpen by taking only 10 microns off the height of the blade, so you'd have to thin less often?
 

McMan

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i would imagine razors coming as rolls of like a 1 kilometer. 25mm wide. you start unrolling the roll and it goes into a furnace where it gets HT'ed. then it goes into another chamber where they quench it. then another chamber on teh same line where they temper it.

and then its probably goes trough a 2 stage sharpening with most likely wheels or belts.

then i gets chopped into pieces.

thats how i would do it at least. just one long continous process.
Pretty close to what's up here:
 

Knife2meatu

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Wouldn't it be great to sharpen in less time? To sharpen by taking only 10 microns off the height of the blade, so you'd have to thin less often?
It's pretty neat, yeah. Highly recommended.

Chips and dents do tend to happen, nevertheless.
 

kayman67

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That's a very good thing.
I thought we could learn how to sharpen efficiently and remove the least amount of metal. Far more than knife makers, a razor company has the challenge of a high ratio of cost of sharpening to the cost of the product.

Wouldn't it be great to sharpen in less time? To sharpen by taking only 10 microns off the height of the blade, so you'd have to thin less often?
Yeah, but maybe things don't really happen as imagined. With these cutting blades, you deal with stress, fatigued alloy and so on. That's what pushing the sharpening process one way or another and not the lack of something else.
 

KingShapton

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Wouldn't it be great to sharpen in less time? To sharpen by taking only 10 microns off the height of the blade, so you'd have to thin less often?
For me, sharpening is a hobby. It relaxes me. I don't pay attention to the time, it takes as long as it takes.

There are different approaches to looking at sharpening. Some look at it more from a scientific point of view, some look at it under an electron microscope, some "over-theorize" sharpening, some talk more about it than actually sharpening it myself, I like to keep things simple and practical.

Sharpening, as a hobby, is a craft, skills that develop with practice and time, passion in some cases. In the best case, with enough interest and passion it becomes a journey that never ends and you never stop discovering and learning new things.

To get back to your question - it would NOT be great to sharpen in less time and to thin less often. Not if sharpening is a journey and that's it for me. I'm not interested in time, it's all about the result.

In other words, I love to cook and discover new dishes, which is also a passion. But because of that I would still have no interest in the work processes in the food industry. It just has nothing to do with what I do and what I want.
 

SeattleB

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For me, sharpening is a hobby. It relaxes me. I don't pay attention to the time, it takes as long as it takes.

* * *
To get back to your question - it would NOT be great to sharpen in less time and to thin less often. Not if sharpening is a journey and that's it for me.
Sounds great. I'm sure there are other discussion threads that would appeal to you more.
 

KingShapton

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Sounds great. I'm sure there are other discussion threads that would appeal to you more.
Just as sure as there is a suitable forum for every thread .....

One thing is always fun to watch - there are always people who spend time and energy to research and find ways to spend less time on sharpening and less time to thin out.

The funny thing is, if you instead invest that time and energy into honing your skills with patience, time, and practice, you would be rewarded with becoming a better sharpener. A better sharpener sharpens in less time and has to thin out less ...

Good luck with your search....
 

DavidPF

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becoming a better sharpener
One way to become a better sharpener is to practice as instructed.

Another way is to reconsider the process and try to understand it better.

In the past, people learning to sharpen were often taught by someone with very strong opinions and a high level of skill. More recently it has often been found that while an old teacher's skill may have been undeniable, a significant proportion of his opinions have turned out to be bunk. Modern teachers of sharpening believe far less bunk and have much more accurate opinions, due in large part to much easier access to evidence-gathering equipment such as appropriate types of microscopes and cameras.

But to claim that modern teachers have it all completely figured out, and there can be nothing left to learn or discover, could involve a certain amount of hubris.

I'd rather have a bright student who explores the possibilities than the kind who does only what I tell them. Bright students don't wait for me to give them a proficiency certificate before they ask questions - if they did, they wouldn't be very bright after all.
 

DavidPF

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  • I wouldn't expect them to have a human visually inspecting for a burr, or visually inspecting to confirm it was removed. What do they do?
I'm speculating, but it's pretty supportable speculation: They're sharpening a [uniform and straight within known tolerances] piece of material, of notionally infinite length. They have a significant budget for factory equipment, and that type of equipment has already been successful for decades. Wasting several metres of material while adjusting the equipment brings negligible cost.

In contrast, the kinds of kitchen knives we usually discuss here are not uniform (two mass-produced knives may be substantially the same as each other, but within itself a knife isn't uniform from tip to heel except in very rare circumstances) and not straight. They're produced in different sizes and have different grinds. Their level of inconsistency would get them rejected from the disposable razor factory in an instant. A machine to sharpen all these non-uniform and inconsistent knives would need extreme adjustability for unexpected parameters, and more importantly a lot of complex calculations involving compromise. Which kind of sounds like a human.

Also, study the edges of brand new Wüsthof knives to see what a generous budget for factory equipment can currently get you, in terms of getting knives sharp.

BUT Despite all that, I still think your questions about what a really effective blade factory can do can be important to knife sharpening, especially when they're kept specific, like the one on burr formation and so on.
 
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