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ZDP - Wow its brittle!

Posted: Sat Jul 03, 2010 4:55 pm
by marcus1
I know I read somewhere on here that for hardness you sacrifice a bit as the steel can be more brittle, but wow, didn't think it would be that noticeable in my Spyderco ZDP Endura :(

I dropped my knife and it hit another metal tool, and the tip lost a nice chunk (The tip was still there, it was the edge that had a chunk out of it... sorry didn't think to take a picture before I fixed it).

I've dropped my G-2 Endura many many times over the 12+ years I've had it and all it has is a bit of a bent tip :)

So either this was just one really unlucky drop, or ZDP is really brittle (IMO).

Good thing I have the diamond stones for my SM... got it back in shape in no time (and perhaps a tear or two later ;) )

Posted: Sat Jul 03, 2010 5:02 pm
by psychophipps
You might have gotten a bum heat treat as ZDP is notoriously very finicky in this regard. Probably not the case as I chipped off the tip of a S30V blade pretty good by dropping it tip-first onto my tile floor before and everyone talks about that steel being the bees knees for toughness.

Posted: Sat Jul 03, 2010 5:05 pm
by marcus1
Hope I didn't get a bum one... I guess I'll find out when I cut through something and find a "tough" spot :)

Posted: Sat Jul 03, 2010 5:30 pm
by The Deacon
Steels like S30V and ZDP-189 are more likely to sustain some damage, either to the tip or edge, when dropped on metal or concrete than many of the older ones. On the other hand, I spent the better part of an hour hacking my way through the branches and vines of a blow down with a ZDP Stretch II, with zero edge damage.

Posted: Sat Jul 03, 2010 7:12 pm
by marcus1
this was on the edge, not the actual tip... Now I understand it his something else very hard (the item is very hard, not the force at which it hit... wasn't a long fall IMO) but still didn't think a "super steel" would chip that easy. I've had to file down the tip some to smooth it and the chip out, but its "scary sharp" again :)

Posted: Sat Jul 03, 2010 7:26 pm
by Water Bug
Hardened steel against hardened steel can be an interesting (and unfortunate) combination. Back in college when out in the field, a friend wanted to borrow my Estwing chisel edge pick. I loaned it to him only to later see him using the hammer end to wack onto the back of a hatchet in order to split a thick tree branch. Bad thing to do!

When I got my chisel edge pick back, there was a large chunk of the hammer end chipped out... surprise, surprise! :mad: Needless to say, since then I ALWAYS ask people their intentions when they ask to borrow something from me.

Posted: Sat Jul 03, 2010 9:15 pm
by Blerv
It's not as brittle as it's hardness would indicate but that doesn't mean it cant chip.

Dropping a knife doesn't happen often but it's really a crap-shoot to what may happen (what it hits and how it impacts).

Posted: Sun Jul 04, 2010 8:35 am
by Seanski
Sorry to hear of that. :( Hope you can grind it out to your satisfaction.
I'm not all that sure it wouldn't have happened though to other types of steel
having fallen on another piece of "metal."

Posted: Mon Jul 05, 2010 10:04 pm
by THG
That sucks. On my ZDP Delica, I've struck the edge pretty hard against a metal dumpster a couple times on accident, and there wasn't even any edge damage to show for it. That's one thing I liked about ZDP-189.

Posted: Tue Jul 06, 2010 9:27 am
by rodloos
psychophipps wrote:Probably not the case as I chipped off the tip of a S30V blade pretty good by dropping it tip-first onto my tile floor
So what goes through your mind when you are standing over a tile floor and your open knife slips out of your hand towards the tile? :D

In my case, I was showing my knife to family members over their tile floor, and my first thought was "Do whatever necessary to NOT let that blade hit the floor" and move my foot to break the fall, followed by "Do NOT let that razor sharp blade hit the top of my foot!" :)

Fortunately I was able to just catch the side of my shoe and slow the fall, making the knife skid sideways across the floor but not breaking the blade (whew). I still get nervous letting family members handle my knives over tile or concrete :rolleyes: .

Posted: Tue Jul 06, 2010 9:40 am
by CombatGrappler
You can't drop any knife on a hard surface and expect it to come through unscathed. Whether it is a Spydie made with the latest and greatest high-tech materials or a Pakistani special that was hammered out on a rock down by the river, it doesn't matter.

Carelessness on the user's part does not constitute a failure on the knife's part.

Posted: Tue Jul 06, 2010 10:56 am
by marcus1
CombatGrappler wrote:You can't drop any knife on a hard surface and expect it to come through unscathed. Whether it is a Spydie made with the latest and greatest high-tech materials or a Pakistani special that was hammered out on a rock down by the river, it doesn't matter.

Carelessness on the user's part does not constitute a failure on the knife's part.
Who ever said I expected it to come out unscathed... and how can you call using a knife Carelessness... i get that some people here like to have what others refer to as "safe queens", but I don't.

I was simply stating that I was shocked that for a "super hard steel" it broke relatively easily... as I stated, My G-2 blade has hit many a hard things and even been used as [gasp I know] a mini pry-bar, and its only got a bit of a bent tip to show for it (which wasn't from prying actually :p :) )

So keep it to constructive criticism or your own experiences please!

Posted: Tue Jul 06, 2010 11:00 am
by Blerv
"Super Steel" is really up to the intended purpose.

If someone made a pocket knife out of axle steel like 4340 they would probably laugh off that drop. People make tomahawks and some swords out of similar steels.

They also hold crappy edges.

Posted: Tue Jul 06, 2010 11:02 am
by ChrisR
I think that is really the salutatory lesson here ... a steel that is hard enough to retain a sharp edge for a very long time is often quite brittle ... hence the common practice of wrapping a hard steel in a soft steel laminate jacket :)

Posted: Tue Jul 06, 2010 11:09 am
by Ski
marcus1 wrote: I was simply stating that I was shocked that for a "super hard steel" it broke relatively easily... as I stated, My G-2 blade has hit many a hard things and even been used as [gasp I know] a mini pry-bar, and its only got a bit of a bent tip to show for it (which wasn't from prying actually :p :) )

So keep it to constructive criticism or your own experiences please!
I put some key words into bold font. I'll do the same in my post.

The super hard steel broke because it favors edge holding and wear resistance over outright strength. GIN-1, which is relatively soft tends to be more resilient, and prying that would break a harder steel may only result in a bent tip. Essentially, you're shocked that a steel exhibited a known characteristic.

It's unreasonable to expect people to not criticize you for unreasonable expectations.

If you were to wear a super hard diamond ring, and accidentally smash it into dust while hammering nails, would you complain that your ring with silver embellishing only dented in the same situation?

Posted: Tue Jul 06, 2010 11:10 am
by The Deacon
Steel generally responds to harsh contact with other hard objects in one of two ways. It either bends/rolls or it chips. The downside, if you choose to see it that way, of ZDP-189 and most of the other "super steels" is that they chip, rather than roll. The choice is either to appreciate them for what they are and what they do well and accept the potential for chipping as part of the package, or to stick with steels which will roll. In that case you will be accepting reduced edge holding as part of the deal. Or search for a knife in a steel which is easy to sharpen, holds an edge forever, and works equally well as as a scalpel and a machete.

FWIW, from where I sit, titling a thread "ZDP-189 Wow its brittle" is no less inaccurate and inflammatory than ascribing any and all accidents to carelessness.

Posted: Tue Jul 06, 2010 11:31 am
by jzmtl
You could break a 1.4116 kitchen knife in half by dropping it on tiles and those are as soft/tough as they come for stainless, so chip in ZDP189 is not entirely surprising.

Posted: Tue Jul 06, 2010 11:58 am
by yablanowitz
Someday I'll learn not to open these threads.

Compare apples to apples. How many other steels hardened to RC 65+ would have fared better? The fact that it chipped when struck at an unknown angle against another piece of steel does not indicate that it is brittle. Just for the record, I have chipped GIN-1/G-2 blades when unexpectedly hitting nails or staples at a shallow angle.

I agree that ZDP-189 is not as tough/is more brittle than GIN-1, but GIN-1 can't hold a candle to ZDP when it comes to wear resistence. Different strokes for different folks.

Posted: Tue Jul 06, 2010 12:06 pm
by marcus1
My last off topic reply in this thread of great reply's mixed with a couple sour apples.

This forum is suppose to be for people to discuss and aid each other in everything Spidie? More over, from the rules:
Do not harass, threaten, embarrass or cause distress or discomfort upon another Spyderco Forum participant or other individual or group.
Ski wrote: It's unreasonable to expect people to not criticize you for unreasonable expectations.

If you were to wear a super hard diamond ring, and accidentally smash it into dust while hammering nails, would you complain that your ring with silver embellishing only dented in the same situation?
What is the point of making these statements. You could have simply stuck with "exhibited a known characteristic". Which, until now was relatively unknown to me... And it IS UNreasonable for anyone to criticize the way I have been in this thread. Be constructive, as most people here have been. To make flippant remarks helps no one!
The Deacon wrote:FWIW, from where I sit, titling a thread "ZDP-189 Wow its brittle" is no less inaccurate and inflammatory than ascribing any and all accidents to carelessness
Why add something like this? Two wrongs make a right? You could have simply stated that you felt the title was misleading due to the information that you so nicely put above it. Which was great; except for the last part.
I've really enjoyed all your replies and have learned from you... so I'm very perplexed at you jumping on me as well!

Something new I've learned from the great people on here... Time for a SANDWICH! :)

Posted: Tue Jul 06, 2010 12:30 pm
by v8r
Back in my Machinist days I found out that Tungsten Carbide lathe bits could be worked lots harder then HighSpeed steel lathe bits. The Tungsten could take off crazy amounts of material at a time, we are talking .250 or more off the diameter at high speeds, but the downfall to the stuff is if you drop that lathe bit the end would shatter.This is due to being super hard/ brittle. High speed steel on the other hand, you could drop and it would just ding it a little due to it not being nearly as hard
I hope this helps folks to understand that if It is super hard it will probably chip or break