You order prime rib or roast beef at an upscale restaurant. The waiter rolls a cart with the beef on it to your table. Then proceeds to sharpen the carving knife on a “steel” like in the following video…
Professional Chef Sharpens a Kitchen Knife - by GotFootageHD.com - YouTube
Then he slices your piece of meat and serves it to you.
Are there metal fragments on your meat from him sharpening the knife? Shouldn’t he have wiped the knife before using it to slice your beef?
Awwww. You are such a cute little flower! The steel that you see in the video is honing the edge, not breaking off metal fragments from the blade. Relax, it’s fine.
I can’t watch the video at the moment but if it’s what i think it is, then No. He’s just bending the edge back into place, not filing a new one.
What they said. Sharpening a good knife should only be done once in a blue moon when it needs it. Honing with a steel doesn’t scrape much off, it just takes out the wiggle.
Plus you need iron in your diet.
A sharpened and wiped knife could similarly leave metal fragments.
Nothing is being left behind that would impact you in any meaningful way. A little more iron in your diet is probably a good thing.
That style of sharpener isn’t grinding off metal. It’s straightens the edge of the blade where it may have folded over. Nothing you can make out with your eyes.
I just honed the blade of a large stainless steel chef’s knife with a honing steel. Made ten or more passes on each side, then wiped the blade with a soft white towel. Couldn’t see so much as a speck of residue from the blade.
There are a few misconceptions here. A honing steel (one coated with ceramic or diamond or sometimes just a ceramic rod) does indeed remove a small amount of material from the blade, and will leave a residue on the blade that should be wiped off. However, it is so small that it does not pose any injury hazard, and the alloyed material is not digestable so it doesn’t pose a health hazard.
An aligning steel (often referred to as a chef’s steel) which is just bare steel and does not remove blade material. It is used, as described, to “align” the edge of a softer steel blade that used to be common with carbon steel knives, but is really not necessary with the much harder chromium-molydbenum-vanadium corrosion-resistant steel alloys, which take and keep an fine edge much better until it wears down sufficiently to require resharpening.
It is untrue that kitchen knives ‘don’t need resharpening’ as long as they are regularly aligned. Although knives used for cutting soft tissue and that aren’t in contact with bone may retain an edge for tens of thousands of cuts, all knife steels will eventually wear with use, and knives that see abrasive or acidic conditions will wear faster. Home kitchen knives that see daily use for preparing personal meals can probably be used with only an annual or biannual sharpening, but knives in commercial service that are in constant use should be resharpened on a monthly basis (although many kitches just buy the cheap plastic-handled knives and toss them when they get dull). Again, the hard stainless steels commonly used in good quality knives will hold a fine edge much longer than the easily-stained carbon steel that was common in older knives. Stainless got a bad reputation for being unsharpenable (or alternatively, couldn’t hold an edge after dulling from use) because the natural stones used for sharpening were not hard enough to sharpen high grade stainless steel; many of these knives require ceramic or diamond sharpening stones (like those made by DMT) in order to hone an edge, and also require good technique to get a consistant edge, else they’ll take a false edge that will wear off quickly.
Most household knives are shockingly dull, to the point that I see people using bread knives to cut delicate fruits like tomatoes because their straight edge knives can’t properly slice. In reality, any decent quality kitchen knife with a plain edge should be able to easily slice a ripe tomato into fine slices without any sawing effort. If your knives aren’t this sharp, they need to be at least touched up if not reprofiled.
Stranger
My kitchen knives are carbon steel, not stainless, maybe 50 years old, and need to be sharpened regularly with a stone. Like weekly. Sometimes I wipe the blade after sharpening, sometimes I don’t. I don’t worry about it.
This is why I cut out the middleman and just sharpen my knives on my teeth.
Steeling a knife in front of a customer is purely show-biz. No knife needs to be steeled several times a day.
I cut out both the middleman and the guy right before him and just sharpen my teeth. 
Here’s a video with Alton Brown showing the difference between honing and sharpening in foam rubber.
Restaurant waiter sharpens knife, then cuts your WHAT?
You shoulda tipped better the last time.
Showbiz is what a lot of steakhouses do, what they charge the big bucks for. One could grill steaks on one’s porch or balcony for a lot cheaper, but not with so much flair (and so much less hair-singeing flare). 
Weekly?:eek::dubious: I have a set of ‘household’ carbon steel knives which I need to sharpen =, well the chef knife perhaps every 3 months or so. It is really obvious when it needs it. The other knives much longer. Sharpening weekly, seems like something is wrong.
As far as I can tell, Alton Brown knows fuck all about sharpening knives. He’s using a honing rod but asserting that it is just realigning the edge (wrong) and he states that sharpening is “best left to the professionals”, although most knife stores and resharpening services use the same ceramic sharpening wheels you can buy yourself. The best way to sharpen a plain edge butcher’s blade or carving knife is with a flat synthetic diamond stone, and anyone can learn to use these to turn even a mediocre quality knife hair-trimming sharp. Alternatively, a portable belt sander can be used, albeit with care for not removing the tip or other profile. Either of these can be purchased for the cost of sharpening a set of kitchen knives two or three times, and can be used on other household implements like scissors, machetes, et cetera. Serrated blades require specialized sharpening tools and a little more work, but again may be readily serviced at home by a non-professional with a little time and determination.
Stranger
Ok, so I am researching this and found someone in a Youtube video sharpening a knife on a piece of leather - called a “strop”.
Doing this leaves some NASTY looking black stuff on that piece of leather! :eek:
So which of the following is that black stuff on the “strop”?
Iron particles?
Carbon steel particles?
Chromium-molydbenum-vanadium steel particles?
And if not iron, is that black stuff a daily nutritional requirement and “good for you”?
Here is the video…
[quote=“Me_Billy, post:17, topic:753313”]
Ok, so I am researching this and found someone in a Youtube video sharpening a knife on a piece of leather - called a “strop”.
Doing this leaves some NASTY looking black stuff on that piece of leather! :eek:
So which of the following is that black stuff on the “strop”?
Iron particles?
Carbon steel particles?
Chromium-molydbenum-vanadium steel particles?
And if not iron, is that black stuff a daily nutritional requirement and “good for you”?
Here is the video…
[/QUOTE]Again, I can’t watch the video were I am at the moment, but I’m betting it’s leather bits.
[quote=“Me_Billy, post:17, topic:753313”]
Ok, so I am researching this and found someone in a Youtube video sharpening a knife on a piece of leather - called a “strop”.
Doing this leaves some NASTY looking black stuff on that piece of leather! :eek:
So which of the following is that black stuff on the “strop”?
Iron particles?
Carbon steel particles?
Chromium-molydbenum-vanadium steel particles?
And if not iron, is that black stuff a daily nutritional requirement and “good for you”?
Here is the video…
[/QUOTE]The guy in the video says he put jeweler’s rouge on the strop, so you’re probably seeing that and very fine metal particles from the knife.