Benchmade Edge Damage Pics

[the possum]

So, last night I had the opportunity to finish off a coon with my relatively new Benchmade folder. I traded for this knife at a show a while back, and just had to go look it up on Benchmade’s site to find out the model name. It’s a 520 Presidio, in 154 CM- got it before I saw the mini Rukus, dagnabbit.

I stuck the coon a few times, and thought I might take a few slashes as well to re-evaluate something… Found out the same old thing there. Slashes like this are utterly worthless with a folder. But I also found out the edge can’t take the bone.

This surprised me just a little bit, since my old Ares folder never got damage this bad doing the same thing, and I thought they were the same steel. No, I’m not surprised that the edge would chip on a high carbide stainless, but maybe didn’t expect it this bad. Hopefully you can see in the photos the deepest chips go halfway up the edge bevel, so they’re right at 0.5mm deep. Edge was formed at around 12 degrees per side, mild convexed, rounding to 15-16 degrees at the edge. Examined under a 20x dissecting microscope, the steel showed signs of very little plastic deformation before breaking. The edge was full of lots of little chips not visible in the pictures as well.

 

[brownshoe]

I've smacked benchmade ats34 into bone w/o damage and it was pretty hard steel (1990s vintage.) The edge was on the thick side. I had a BM spike blade with heat discoloration at the tip, probably from sharpening. Kind of made me nervouse...what does it do to the temper? I sent it back and benchmade replaced it for free. Maybe your blade has some problem, send it to benchmade. They are pretty fair. If they don't replace it for free, blade replacements run about $25.

 

[the possum]

I think I'll hang off on that for now, since I just sharpened out the damage. Edge must've been burned or something from the factory.

I thought about mentioning this in my first post, but when I first got it home, I took it to my diamond hones to knock down the shoulder where the primary grinds and edge bevels meet, and add a microbevel to smooth up the factory edge. I remembered thinking then the steel seemed very soft on my stones; it worked easier than 420 stainless from Case. I was worried it might be underhardened. But now, I took it to the coarse stones to remove the chips, and brought it back to the diamonds and it feels like a totally different knife. Now the steel actually feels like something approaching 60 Rc.

Dang. Wish I had done some more formal testing on the factory edge to compare with...

 

[thombrogan]

You know, a 154CM folding pocket knife has no place doing a bainite L6 falchion's job. Even if the sword is your dad's and not yours.

 

[the possum]

I did have the big bowie at hand, but I figured it wasn't necessary. I did use the bowie to lop the head off another one the other day though...

Haven't made any time to get out in the shop to work on Dad's falchion. It's still a roughly shaped 8 pound bar of steel...

I should also note I'm not willing to completely dismiss the above edge damage to a burned edge; I'll still be keeping a close eye on it.

 

[thombrogan]

Sorry to hear about the Falchion. I have a dopey homage to the overated santoku that's still a 2" x 12" power hacksaw blade.

 

[hardheart]

there's a few complaint threads on the BM forum about edge chipping on the 154.

 

[Cliff Stamp]

The damage is fairly intense (deep) for a burned edge. It isn't surprising to me, though fairly idiotic behavior considering the intended use of "tactical" knives.

-Cliff

 

[hardheart]

Behavior of the blade/edge, correct? Before there's gross misunderstandings and statements by others.

 

[Cliff Stamp]

Yeah, I see what you mean though, it could be taken as I was critizing Possum, sloppy language on my part. Thanks for pointing that out.

-Cliff

 

[thombrogan]

It was unseemly behavior on the possum's part, too.

Tactical folders are tough, ready for the hardest, most dangerous actions under the most strenuous conditions. Therefore, anything beyond opening the plastic wrappers and breaking down the cardboard box of some Hot Pockets is completely abusive and should be disregarded.

 

[HoB]

Ouch, so true. . I am sure that Possum just doesn't know what he is doing and the "coon" was actually a wolverine with bones laced with adamantium .

 

[the possum]

I'm pretty sure Wolverine could eat me for lunch. He'd need a lot of beer to wash down my nasty fat a$$ though.

On the subject of edges vs. bone, I got a doe during local muzzle loader season a couple weeks ago. I did the processing myself of course. Why pay somebody else to play with knives? After I had the meat taken care of, the ribcage/spine assembly was laying on the table, so I convinced myself I *really needed* to use my knives to break it down for easier disposal. Since I already knew what my bowie was capable of, I mostly just compared my Blackjack model 1-7 against an old F. Dick butcher knife I was using.

I think both those knives are about the same weight, as the Blackjack's blade is much thicker. The butcher knife of course is thin, with an edge to match. (much thinner than even an Old Hickory butcher knife, and probably about half as thick as the Benchmade folder above, though I haven't measured it.)
Here is a picture of a different butcher knife that's almost identical in proportions:

I chopped with both knives against the ribs and spine, and the longer butcher knife had at least 3 to 4 times the cutting/chopping ability as the Blackjack. I whacked the neck off clean like 3 times, and did at least another dozen cuts against the bone before I got a ripple in the edge. No chips. The Blackjack's edge held up just fine, as it had more support behind it, but its cutting power certainly wasn't impressive either.

 

[pogo]

Bones are tough to cut or chop with any knife/steel. I am surprised that the Benchcrud chipped considering it is fairly expensive. I would send it back for repair as the heat treat appears flawed. JMHO.

 

[the possum]

Bones are tough to cut or chop with any knife/steel.

Actually the point of my last post was to show they really aren't for carbon steels at least. The spine and ribs of a deer are quite a bit more challenging than anything in a coon, except for the teeth. Deer leg bones are another story, I admit, but some steels can easily handle tasks that destroy others.

 

[yoda4561]

I was rather suprised yesterday at the durability of my 710's edge (ats-34). I had some 3/4" emt (steel pipe) that needed reamed since it was cut by "something" that left a huge amount of flash inside the pipe. My normal channel lock reaming method wasn't doing much so I figured "what the hell. I busted out the 710 and started cutting off the steel flashing, sometimes the edge would grab the inside of the pipe and chatter along a bit. Now it's chipped out before doing much easier stuff than this, and I always resharpen it as thin as I can (the blade is as flat to the stone as the thumbstud allows) so I expected to see a few small chunks missing. To my surprise it was merely dulled a bit, probably some microchipping but a few swipes on my diamond rod cleaned the edge right up.