Why convex isn’t a “stronger” edge…

[Josh]

I should have stayed online to make sure the photos loaded. Strange that they didn’t, as I compressed them quite a bit. Even cropped them. Here I’ll try again. Since Leo already got the right overall, I’ll skip it.

Yes, the knife is heavy. That bolster is a solid chunk of stainless, forged with the blade. The handle looks to be a micarta, maybe of ironwood. Again, I didn’t sense that the edge was overly hard (untempered) but clearly, something’s wrong.

Thanks for looking it up, Leo. I’ll tell her to take it back and ask for a warranty replacement.

Josh, I completely agree with you that the convex cannot be stronger than a normal v-edge of the same angle. I’m simply offering that maybe the claim originally was made as compared to a knife which has an edge angle continued from the same primary grind planes. For example, if the 15-degree grinds had been continued out to the apex.

dude that is jacked!!! yeah, good call on the warranty replacement!

yeah, full convex is definitely optimum! 🙂

[Leo Barr]

The handle is Pakka like Shuns so a goos resin based wood looking handle . That crack is as I would have said when playing Conkers that is a death crack it has gone through to the cladding the whole knife is toast.
It also looks as if there are stress fractures panning out from that running parallel every 1 / 2 mm it looks like a handsome edge although the knife looks way too thick to cut well I would say the secondary bevel needs raising to about 1/3 up the blade to get a descent profile .
This seems to be how cheap knives are shaped supermarket knives all seem to be like this they are fine for cutting pre siced foods or opening plastic wraps but they fail miserable for cooking .
Its a pity that they have produced a laminated knife with such a poor profile .It did say in the blurb

Designer thoughts
“My idea with the SLITBAR series was to create kitchen knives that you can have on show to give character to your kitchen. For their modern and distinctive look, I took my inspiration from Asian design. Of course it’s just as important that the knives are functional, comfortable to use – and that they age well. I also wanted to include many different types of knives in the series, so that you always have the right one, no matter what kind of food you’re cooking.”
Designer Mårten Cyrén.

That essentially the knife is for show and I think this was the main design idea utility after .

Sorry to be so critical of the knife but unless you are going to thin the next on decently it is never going to be a good knife and I suspect that the next one will have the same cracking problems perhaps a better bet would be to ask for the money back and perhaps put it towards a good entry level Japanese knife like a Mac.

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[Leo Barr]

I just want show you what I would consider a good blade shape this knife is a Mac and it was originally a Santuku that had a very large chip out to the centre of the blade from an Avocado stone over time I have got this knife right initially when I slowly ground off on an Edge Pro I had a reasonable edge but the edge was probable about a third up the blade it was sharp but pretty useless so eventually after a couple of goes I have got the right amount of taper and shape to the blade probable resembling the sort of profile it had when new once again it cuts properly passing through most things easily . These cheaper knives will never perform properly unless they are radically thinned and I am not sire that you can do the secondary bevel on the WE since it needs to be sub 10˚ probable 5-7˚ I would imagine having done this on bench stones I cannot say what angle it is on this knife probable about 1 coin thickness under the spine but I do not use coins the primary bevel is probable about 12˚per side as an estimate .

The spine mid way along the knife is 1.65 mm the thickness of the blade about 1cm above the primary bevel mid way along the knife is about 1.15mm – 2.5mm above the primary bevel the blade is 0.5mm. These are more the sort of proportions you should be looking for in a knife I think the Ikea knife is probable well over 1mm thick

2.5 mm above the primary bevel

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[Josh]

In the process of skinning and harvesting a deer for example, its inevitable that your blade is going to contact bone.

And the bone is hard so it can can chip or damage the Steel.

When you take out the backstraps you have to glide your blade along the bone and carve out the meat. Also when you remove the legg muscles you have the chance of hitting the legg bone.

What you want is a balance of a knife edge angle that is durable enough to not take damage from the bone, while still being sharp enough to cut the skin and meat.

Which is why I think Convexing is preferred on hunting knives because it gives the edge more support for durability and it helps the blade to glide along a bone instead of trying to cut into it.

But if you were a Fur Skinner who did not butcher the meat and did not worry about bone, then you could take it as far as you like. And it would not matter if the blade is convex or not.

So I think the purpose of the knife really dictates what kind of an Angle you should put on it. Its situationally dependent on weather or not you think the knife will contact bone.

Here is an example of something you should probably not do.

Dont take your new 3V Steel Bark River and v grind it down to 15 degree and use it to take a Trophy head off a Stag.

You are just begging to chip it.

Figured I would bring this conversation here 😉 see above and let the discussion begin!

[Author]

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