Kitchen knives that never need sharpening?

Just seen some knives in Tesco that allegedly never need sharpening! Scam? Or possible? What's the technology?

Reply to
Chris
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Chris wrote in news:fm5H9XCyKs9BFwWb@[127.0.0.1]:

You regularly buy new ones?

Reply to
Rod Hewitt

We bought one of those 'Kitchen Devil' general purpose kitchen knives quite a few years ago and recently (whilst I was hacking up some big root veg for a stew) had the blade break out of the handle.

Because it was so handy I went out and bought another (£2.99 or summat) and noted on the package that it was 'guaranteed for life'.

I stuck the broken knife in the new knife's packaging (to make it safe in the post) and returned it with (an honest) covering note.

I got a new replacement a few days later with a note apologizing for "the failure of the product", but added that "the model was *last* produced over 12 years ago!" ;-)

All the best ..

T i m

Reply to
T i m

Probably Titanium coated knife edges, they will stay reasonably sharp for a long time but when they eventualy go dull you will not be able to sharpen them.

Reply to
Kaiser

Titanium Nitride is a golden colour, and forms a wear resistant and fairly slippery coating. You can sharpen, but you're then back to the base metal.

Titanium (metal) doesn't make good knives, and is only used in very unusual circumstances - diving knives, where its seawater resistance is needed, for example.

Titanium (metal) coating is never (?) used on cutting tools, as titanium isn't really any good for that.

They may be saw-edged ones, which though they will cut and go on cutting things for a longer time than a straight blade, will not produce as clean a cut. You can't just chop with them (when slightly blunt) but need to saw.

Reply to
Ian Stirling

If the guarantee says so, then keep them to it! But no, there is no such thing as a knife that never needs sharpening. Steel this hard is extremely difficult to get a good edge on, but will keep the edge for a long time (assuming you don't cut onto metal, glass or ceramic - wood/plastic only if you care about your knife!). When the edge goes, it's again very hard to sharpen (and isn't really possible in practical terms).

I find this type of knife (Kitchen Devils are a good example) are nice and cheap and good for everyday slicing & dicing. I sharpen them as best I can with a ceramic sharpener maybe 2/3 times a year and it keeps them good for rough chopping veg and slicing up meat.

However, expensive knives are a beautiful treat after them and a must for fine chopping or carving (or filleting if you do it). Real easy to sharpen with some good wetstones and bring a scary sharp edge to, but need far more TLC to keep good!

Hope this helps - if you can't be bothered caring for knives, buy the stainless, hard, cheap ones and replace every year or so (or send them back blunt and see what happens!). If you can be bothered, spend the extra money for a couple of really good knives, care for them well and enter a new world of cutting things translucently thin!!

a
Reply to
al

Yes, been around about 20 years now.

Personally I'd rather have knives that were really sharp in the first place - buy some Globals.

Reply to
Andy Dingley

I was under the impression that these cannot be sharpened with a steel or a conventional knife sharpener, but only with a green grit wheel or diamond file ect.?

Reply to
Kaiser

Once you wear off the coating (however it's done), you are just back to the underlying metal.

Reply to
Ian Stirling

I've had an inexpens .. no, let's be honest, 'cheap' (!) Prestige carving/bread "never needs sharpening" knife with a scalloped edge for 30 years or more, and even though it's cheap hard metal, I can still get a good edge on it with a sharpening steel. Mind you, it's not as 'scalloped' as it used to be .. ;o)

Reply to
Mike Faithfull

"Laseredge" (IIRC) are like this. I had one that served as a good all round knife for a few years, and still sometimes gets used as a steak knife. Not as sharp as it used to be though.

Reply to
Chris Hodges

Cheap and soft blades are easy to sharpen, but never get *really* sharp and loose their edge too quickly. However, you can still sharpen them far better than most people know knives are meant to be so by all means go this route.

If you get a chance though, check out a knife shop (please not some crappy up-market department store with morons for staff!) and get a demo of a really good knife. Over about £40 generally for a good size chef's or carver.

I like Japanese knives personally and have a beautiful Damascus steel carver and chef's knife. About £80 each. I also have a collection of other reasonable knives (£100 set) to cover all other eventualities and everyday use.

a
Reply to
al

Globals are great, great knives. I just prefer the feel of wooden handles ones. Always try before you buy to make sure you like the weight, balance and feel.

a
Reply to
al

Just seen some knives in Tesco that allegedly never need sharpening! Scam? Or possible? What's the technology?

Don't know, but we just got an Ice Bear ceramic zirconium knife from Axminster. Apparently it's only posible to sharpen it with a diamond whetstone - if it ever needs it. This thing is so sharp it's scary. Dave

Reply to
Dave

It's quite a simple equation when it comes to sharpening really. The material you sharpen with has to be harder than the blade you're sharpening. Otherwise it can't grind away the metal/ceramic.

You can quite easily buy sharpeners for ceramic and other hard blades (just because the word "diamond" is mentioned, doesn't mean Pussy Galore's about to come marching in!!). However, hard blades will never hold a good edge as you just can't sharpen it like a good workable metal blade.

a
Reply to
al

I would dearly love to own and use some good quality knives, but I'm afraid 'The Management' lacks a certain empathy with such things and I'm sure she would all too quickly damage either them or herself ...

Like she says "I look after your shirts, you look after my car ..." Seems to work!

Reply to
Mike Faithfull

Kitchen knives that never need sharpening only need sharpening when they get a bit blunt. Same as ordinary knives really. Scalloped edges easier to get a good edge however - for ordinary purposes like cutting bread. Best knife we have was grandparents carving knife - very ordinary sheffield plain steel not stainless with "ivory" handle. Must be 80 years old or more and apparently indestructible and keeps good edge with use of a matching steel which is worn nearly smooth. Got the matching carving fork too - does a brill job on the old sunday joint (meat that is).

cheers

Jacob

Reply to
jacob

I know not a true 'edge' like some of the knives being mentioned here but I can't remember EVER sharpening the Kitchen Devil 'utility' knife in the 10 odd years we had it. And that was after cutting basically 'anything' that needed cutting including cardboard boxes and those hard plastic straps you get round big packages. I would grab it even going for a craft knife if I wanted to cut something softish, quickly. 'She' would then have to track it down "why isn't the Devil in the draw?" sorta thing ;-) It would still do a good job on a tomato?

Same as ordinary knives really. Scalloped edges

LOL. We rarely have a 'joint' (of meat) and if we do we (she) manages to cut it up with 'something' (don't think we have a 'carving knife' at all).

All the best ..

T i m

Reply to
T i m

A point demonstrated by the guys in the kebab shop who seem to re-sharpen their long carving blades at every carving?

All the best ..

T i m

Reply to
T i m

Indeed. Actually, they're not sharpening the blade all the time. If they were it would wear away too quickly. What a steel does is true the edge. At a microscopic level (and often not if you cut onto hard surfaces!!), the blade folds over slightly when you use it and looses its edge. Using a steel shouldn't really remove any metal (your steel should be just that - not some nasty ultra abrasive thing!), it's just meant to true the blade again and should be done almost every time you use the knife, depending on the softness of the blade. Helps keep a perfect edge.

Then every month or so perhaps (depends on how much it's used ... but in a kebab shop, I should think at least this often) it is professionally sharpened using stones (ie. you are removing metal to form the correct blade angles again). If the blade is thick at the top and thin at the bottom like a cleaver, this will eventually not be possible as you'd need to remove too much metal to produce the cutting angle. With a constant thickness blade, you'll eventually (many many years) just wear upwards.

a
Reply to
al

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