Last week, I visited Solingen, Germany's "city of blades," where knives, swords, and the like have been made for centuries. In between sipping beers and munching wursts, I paid a visit to the factory of Zwilling J.A. Henckels, at their kind invitation, to peer at the semi-roboticized lines where they produce their knives.
The raw material comes into the factory on huge spools of sheet steel, each sheet the thickness of a knife. The steel is cut into individual blanks, destined to become individual knives. About three weeks elapse between when a blank comes off the spool and when it emerges, a finished knife, at the other end.
In my breathless tour of the factory, I watched as a giant press cut and stacked the blanks, which are made of the company's secret blend of stainless "special formula steel." The blank is transported to another building, where the first of the factory's 90-odd industrial robot arms takes it in hand.
In the classic design, the knife has a thickening where the blade meets the handle (aka the bolster). This is formed first, by heating the middle of the blank, and then pressing the metal's two ends together so the molten middle bulges and widens, in a process that my contact specifies is called upset forging. Next, a drop forge shapes the bolster, before the blank is quickly cropped into the rough shape of the knife it's going to be.
After that, it proceeds through a series of cooling, supercooling, and heat-tempering steps that give it its corrosion resistance and toughness. This is one of the benefits of the special steel, I'm told -- it heats and cools in very predictable ways, allowing the factory to use more precise temperatures rather than temperature ranges.
After the tempering, any distortions or warpings that the heat has created in the blade are hammered out by a highly skilled human, who picks up and eyes each knife, one at a time, and flattens any that need flattening with precise strokes of a little hammer.
The knife passes into the hands of another series of robots, which use grinding wheels to narrow down the thickish blank into the tapered contour of a blade. Only roughly, though -- the fine grinding and sharpening, as well as putting on the handles, is left to the factory's humans, who wear puffy gray overalls and exude the confidence that comes with being extremely good at your job, and quite possibly coming from a line of knifemakers generations old. Wooden handles are glued onto the tang of the knife and then riveted in place; plastic handles are simply melted on by heating the tang and inserting it in a ready handle. The edges of the handles are smoothed by robots.
Finally the knife is cleaned and passes onward to the scrutiny of the quality assurance women. If it has no flaws -- there's a big photo-book of possible flaws -- it gets packed up and winds up in someone's kitchen.
Check out the step-by-step gallery of pictures from the knifemaking process.
This is really cool, but have you ever seen them make Damascus blades? That is amazing.
I made a carbon steel chefs knife before. all we had was a sheet of carbon steel, then we had to cut it out, fold it, hammer it, etc. Then sharpen it. It was an interesting process
Really cool video. I would love to attempt to make my own knife or sword. An injured shoulder, wrist and back probably would make that near impossible though.
Impressive Factory, but sad to see that most jobs have been eliminated and replaced by robots. They even push the buttons on the machines which used to be operated by actual people.
Yes, I know, robots don't sleep, robots don't ask for a raise, robots don't get hurt on the job - but you know what!?
Robots also don't buy knives, and they don't have families who buy knives ...
"Learn to Live & Live to Learn"
Alexander von Humboldt
The Henckels knife i bought was marked "Made In China" in small print. I returned the knife, it was not Henckels quality.
"Robots also don't buy knives, and they don't have families who buy knives "
"Do not offer sympathy to the mentally ill.
Tell them firmly:
I am not paid to listen to this drivel.
You are a terminal boob." - William S. Burroughs
Ohhh sooo coooll......Whats next???? taking us deep inside the workings of a paper mill.
There's always someone countefeiting well-known high quality products. Sounds to me like you have one.
I am only allowed that funny little plastic spork in my house. Now what's up with that! :)
Henckels has the single man logo, the double man logo. The set that you had was obviously the Henckels International (cheaper) set. Try their double man logo knives out, you won't be disappointed.
You knife makers will find this link to be a major breakthru. http://jmichaelphotography.com/icemandoublegrinder.htm
This machine makes it possible to form a hand made knife in minutes. Take notice of the of the double line of sparks, it is cutting and making matching bevels on both side of the knife. That is the art of knifemaking that takes years to master. This machine vastly simplies that process.
I was very interested to see that the bolster is formed from compressing the material lengthwise ("upset forging"). I had always presumed that they would have milled the entire knife out of stock thick enough for that thickest section. This makes a lot more sense. But these knives have been made to this specification for many years, and supposedly since before the advent of automation, such as upset forging, so I would be interested to hear how they accomplished the thicker bolster feature in the old days!
The heat treating process, together with the metallurgy of the blade, makes for a total package of high quality that confirms my expectations. I first saw the slide show that a friend sent to me, and no brand name was to be found. I thought, "if this isn't the Henckels factory, I'll be amazed." It just had that look and feel about it. Then when they showed the cooling tanks using liquid nitrogen, it was a done deal for me. I only needed to find the article to confirm my suspicion. And it was confirmed.
The article does not explain what the advantage of the bolster is, but I have heard that not only does the blade thereby become easier to clean, since food particles do not have any cracks to hide in, where the handle is connected, but also, with age, the handles cannot slide down the knife with heavy use, and the rivets are much less likely to cause the wood to split from sliding handles. I'm not sure how that figures with plastic handles, but perhaps the plastic is more durable, too, against the bolster, rather than have the blade one thickness over its entire length, like all the cheap knives have. How many of those have you seen with broken handles?
The article mentions that wood handles are glued and riveted on and plastic handles are simply heat-pressed into place (which requires much less skill). It does not explain, however, that the superior wood handles are not exported to the USA, and that the only way for Americans to get them is to go to Germany and bring them home with you (or have them shipped). Good luck now, with the new "terrorist" rules. If you do get wood handle knives, you should not wash them in the dishwasher. Wash by hand only. No question, wood handles are the greatest, and these knives are truly works of art. If they're not abused, Zwilling J.A. Henckels last a lifetime. If you don't know what you're doing, you should have a skilled sharpening service maintain the edge for you, and pay attention to what they tell you regarding use.
There's no shortage of shops in Germany where you can see the variety of specialty knives available. I got a fish fillet knife that's got a 20" long blade, specifically to slice watermelon into various thicknesses. The sales lady was a bit worried about my intentions, and I was amused with her German predisposition: specialty knives should be used for the special purpose for which they were designed! I spent a few minutes with her, though, and she eventually was convinced it would be okay. Now that's honesty in sales, eh? The buyer has to sell his idea to the salesperson! When I got home and tried it out, I was duly impressed. I can slice a large watermelon into 1/2" thick slabs quickly and with ease using this knife, and the same task is impossible without it! Having the right tools for the job is half the battle!
The place-setting steak knives have been only available with plastic handles since before 1985, in my experience. So if you come across a wood handled Henckels place-setting steak knife, you might have a rare item. I found one lying on the street one day, having been hit by cars. I sharpened it and buffed it up, used it for about 4 years, and it just gets better with age. It seems to be happy now that it's being cared for! HAHAHA
I have the chinese built Henckels knifes. Talk about crap. They are stainless but have rust stains on them and half the time the serrated blades tear rather than cut. Not happy considered they cost over $100 (even though they were a wedding gift). Years ago, I bought a cheap Faberware set of knives for my mother and to this day, they are sharp and not a single spot of rust. My father has knives over 30 years old with no problems either.
Science always asks "can we," but doesn't seem to ask "should we."
Thank you for this article its in depth information has helped me greatly.
Can some one help me find the dimensions of the machines?
Its for a project where we make a company that produces a product through a "automatic" productive process, and I need to make a diorama of that process (to scale).
Thank you for any help, and sorry if this isn't the kind of thing that should be posted here.