Ceramic Knives & The London Bridge Attack

On June 03, 2017, three men drove a van into crowds on London Bridge, and then exited the crashed vehicle and began attacking people with knives, in an act of Islamic terrorism.
In the past few days, Scotland Yard has released photographs of the weapons used in the attack, and identified the knives as being Ernesto brand kitchen knives, purchased at a Lidl store. However, in that release, and since then, they have erroneously identified the knives as being made of ceramic.

Many people have shared this information, and included advice about the benefits, or warnings about the security risks, of ceramic knives (which lack a metallic signature). Unfortunately, they are propagating either an error on the part of Scotland Yard, or a politically charged narrative useful to the anti-knife government of the UK.
Viewing the pictures supplied by Scotland Yard, and looking at the Lidl website listing for the exact model of knife pictured, it seems quite clear that the knives are Stainless Steel. It says so on the website, and their appearance (including the damage to the blade pictured) is very consistent with a steel material. However, there’s a great deal of resistance to this idea from many people.
I’d like to examine the evidence with some detail.


Evidence Photos of Knife Recovered from London Bridge Terror Attack. Left Side Clearly Labeled "Ernesto".

Evidence Photos of Knife Recovered from London Bridge Terror Attack.
Left Side Clearly Labeled “Ernesto”.

Above is one of the evidence photographs released by Scotland Yard of a knife used in the London Bridge attack. In this article from The Guardian, the knives are identified as Ernesto brand purchased at Lidl.
Looking at the large blade, the distinctive coloration, and the straight-backed handle design with angular pommel end, the only knife in Lidl’s Ernesto line-up that matches (and it’s an exact match), is the Ernesto Kushino-Messer 32cm. Astute readers who can read German, or translate the page in their browser, will notice that these knives are listed as being Stainless Steel.
Those with an investigative bent will go look at the other Ernesto brand knives, and see that while they make ceramic knives, those offerings are distinctly different: None of them are that large, the largest being 16cm, and none of them have brightly colored blades. They are also a distinctly different design, being both smaller and with curved handles that drop to a rounded pommel.


Honestly, this should be the end of the discussion. Many folks aren’t satisfied by this, however, and the ceramic narrative persists. As a custom knife-maker, I have found that a lot of people have difficulty discerning one knife design from another, and an even greater time recognizing the visual differences between materials. Taking that into consideration, let’s ignore that the knife in evidence photos is exactly the same as the model listed on Lidl, and look at just what we can learn from those evidence photos.


In the above crop of the evidence photo, if you look closely where the arrows indicate you can see some less readily apparent damage. Behind the large chip (blue arrow) you can see that the edge of the knife appears narrower. This is consistent with edge-rolling from damage, which does not occur with far more brittle ceramic knives. Looking ahead of the large chip (red arrow) you can see another spot of edge deformation, where the edge is significantly rolled rather than having chipped away. Again, this is something that cannot occur with ceramic. The more brittle ceramic would simply chip cleanly at each of those points.
But, what about that broken tip and large chip out of the edge, many people ask. Yes, ceramic knives can break like that, but, so can steel knives. It is very possible for steel to break cleanly without visible deformation, in the manner seen in the evidence photos, given that it has a crystalline structure. In fact, it’s fairly common breakage that’s not at all hard to find examples of in a random Google search, for example HereHere, Here, Here, Here, Here, and Here.
In making these observations, I should point out that I have been a knifemaker for nearly 18 years, working in steel, titanium and yes, ceramic. I have made and repaired knives made from all of those materials, to include both steel and ceramic kitchen knives. The break and damage patterns shown on the London Bridge knife are consistent with a steel material, and inconsistent with a ceramic material.

Some are claiming that the knife in evidence appears to be colored through-out, since there’s no shiny steel visible around the chipped out area. This claim fails to recognize that the evidence photos released by Scotland Yard are taken at 90-degree’s to the knife, and the direction of light puts shadow on the broken edges of the blade. That is why there is no tell-tale reflection from the edge of the chip, to indicate the material of the knife.
Some have asked why the coating isn’t, then, obviously flaked away from the damage. Take note of the above linked photos of broken knives, where coating is present it stays intact right to the edge of the break.
Most ceramic knives are white or black, with some being a gray tone. Many of those knives are then coated with a bright coating as is popular in kitchen cutlery at present, but very few of them are actually made with dyed ceramic. When a knife is made with dyed ceramic, it is easy to tell because the color is not uniform. There will be a transition effect from the thickest part of the blade (the spine) to the thinnest (the edge), and the color will be more translucent at the thinnest part of the knife. This can be seen Here. Compare that to the London Bridge attack knife, which is a uniform color from one side to the other, indicating that not only is it just a coated blade, but that the coloration and appearance at the edge or break has nothing to do with the nature of the material it’s made from. Even were it a solid color dyed ceramic material it would not appear uniformly colored throughout. The claim that it is ceramic because of its color is false, because of the angle of the photograph and the properties of dyed ceramic knife blades.

Why has Scotland Yard claimed the knives used in the attack to be ceramic? Hard to say. The UK has a long, and increasing, history of being strongly anti-knife. Given that Scotland Yard’s counter terror guys tend to be rather good at their jobs, but that politics runs deeply though all facets of British government, it may be possible that they’re working a narrative towards the goal of further knife restrictions. (Remember, this is the nation that was at one point quite taken with the idea that all kitchen knives should be made without points, to prevent violence).
It is also possible, even more likely perhaps, that a simple mistake was made. One of the other knives used, and not shown to media, may have been ceramic. Or, someone confused a detail in recording the evidence, and conflated having a ceramic coating, with being a ceramic blade. A similar knife, made by Cuisinart for the US market, is clearly marketed as having a “ceramic coating”, and it’s not much of a stretch to suspect that somewhere in the Ernesto marketing a similar statement is made. Ceramic coatings are currently common on even low-end kitchen cutlery, as a “non-stick” feature. It might not be hard to get the two things confused, after all such confusion is very common among knife users here, who often conflate titanium nitride coatings with being a titanium blade.
Whatever the reasoning or cause, the reported “facts” are not correct – The knife pictured in the photos released to the media is not a ceramic knife. It is in no way consistent with the appearance, or properties, of a ceramic knife. And, the exact model of knife has been officially identified, and is listed on the primary retailer as being made from Stainless Steel.

As a final note – Had the London attackers purchased and used ceramic kitchen knives, they would have fared no better at passing through metal detectors. Ceramic knife manufacturers insert a steel-shank into the molded handles as a security precaution, against exactly that threat.

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