Got my ZT561 from repair

[Luis G.]

So I bought a Zt 561 a while ago and had to send it in for repair due to a sticky lock.

Other issues were: grinding noises/uneven friction due to the detent ball and the carved path it made on the blade.

So far I am happy, they recarbadized the entire lockbar (this time properly done, when i was new it was barely carbidized which was probably why it developed sticky lock so soon), and must of hardened the tang contact surface due to discoloration.
Also they apparently used some time of graphite powder on the detent ball path.

Only one rather minor but major gripe.
They resharpened the knife after what took me 4 hours to reprofile. I had specified in the form not to resharpen it. But they did anyhow.

This will mean I will loose more steel when I reprofile it to 20 degrees... again. Like I said a minor grip to some whom dont care but a major gripe for me since I will need to reprofile it.

Either way I am glad to have my knife back as I missed it.

 

[SchweetGuitars]

Bummer bro!

 

[chester22]

Stinks that happened but glad it's back and good as new

 

[asm3686]

i can imagine your frustration i spent about 3 hours reprofiling a s30 blur to 20 degrees and i would like to do it to more of my knives because the edge is wicked sharp but i cant justify the time it takes and i imagine it would take even longer on and elmax blade

 

[oregon]

Thank you for this thread Luis G.

If I understand you, your ZT 561 was sent back to the manufacturer for warranty service where it was determined that the lockbar contact surface was not properly carbidized so they carbidized it again, a process where electricity is arced from a hard metal electrode depositing the electrode's hard metal onto the titanium surface. Have I got this correct?

I didn't not know that ZT carbidized the lockbar surfaces during their manufacture.

Is there a way to visually determine whether or not the lockbar has been carbidized at all and, if so, can you tell a good job vs a not so good job of carbidizing? Thank you.

A few pics of my 561, no problems with this terrific knife, to show the targeted parts of the knife for your amusement:

 

[Luis G.]

Thank you for this thread Luis G.

If I understand you, your ZT 561 was sent back to the manufacturer for warranty service where it was determined that the lockbar contact surface was not properly carbidized so they carbidized it again, a process where electricity is arced from a hard metal electrode depositing the electrode's hard metal onto the titanium surface. Have I got this correct?

I didn't not know that ZT carbidized the lockbar surfaces during their manufacture.

Is there a way to visually determine whether or not the lockbar has been carbidized at all and, if so, can you tell a good job vs a not so good job of carbidizing? Thank you.

A few pics of my 561, no problems with this terrific knife, to show the targeted parts of the knife for your amusement:

Carbidizing can mean two things from my understanding: Microwelding carbides unto the surface, or literally creating titanium carbide on the titanium it self (I am unsure how this process happens, what I do know is that it is expensive).
In the knife industry it appears they weld tungsten carbides, versus carbidizing the actual titanium. More than likely as a cost saving measure.

ZT never mentioned what they found wrong or what they fixed. They just said it was repaired.
The carbidizing was redone because when I sent it in what little it had out of the box had "chipped" off.
Lastly the blade tang has discoloration that was not there before and appears to be from hardening.

They do carbidize the frame lock from production for the ZT560/ZT561, mine out of the box however was not done properly I believe (half carbidized).
Anyways this is what true carbidizing in the knife industry is, you can see the crystalline structure of the carbides and it's "rough" appearance". When done properly it's way better than heat treating titanium (ex: CRK's method), and provides an extremely hard surface.

And lastly here's a video of carbidizing. The machine runs like $200-$300. Im sure there's others that are more expensive.
http://www.youtube.com/watch?v=x4JptL4nCi4

 

[oregon]

Thank you kindly LG for the photos and the explanation.

There are a buch of videos of showing how a thin layer of Tungsten is applied to the lockbar mating face. Fascinating stuff. Here are links to a couple: http://www.youtube.com/watch?v=x4JptL4nCi4 & http://www.youtube.com/watch?v=5EONC0WTSxQ

I can't swear that your lockbar face has had Tungsten placed onto it. The freshly carbidized surfaces in the videos look quite shiny, like Tungsten looks. And, now that I've watched three videos about plating with Tungsten I don't see any Tungsten on my lockbar mating surface. It looks like unadulterated Titanium to me. This makes me think, IMHO, that ZT doesn't carbidize the lockbar during manufacturing.

It is cool that anyone with one of these electric tools can build a hard surface on worn or sticky parts of the locking mechanism to fix problems and extend the working life of the knife.

 

[Luis G.]

First off what you see in my pictures is tunsgten carbidizing. No doubt about it, it is not the first time I've seen it in person. What you see on the tang is like I said, hardening not carbides thus the discoloration.
You can't really tell from the side too well. Take it apart and take a look.

I emailed them about lockbar surface carbidizing a while back and Kershaw responded saying they do carbidizie the lockbar surfaces and like I said out of the box new there was carbodizing but maybe not entirely as a patch was missing:

Luis,

Thank you for your interest in our products. Here is the information I believe you are looking for:

1. The material used for the liner on the 0561 is 410 Stainless steel

2. The pocket clip is also the same 410 Stainless

3. The lockbar surfaces are carbodized.

5. The lockbar stabilizer is also 410Stainless
6. We can warranty a blade if you send the knife in to us, however we do not mail out or sell spare blades to the public.

Hope those answered your questions.

Best regards,

Ronda Wallace

Kai USA ltd.
International Customer Service Rep
Kershaw & Zero Tolerance
18600 SW Teton Ave.
Tualatin, OR 97062

F: 503.682.7168
P: 800.325.2891 x1157
rwallace@kai-usa.com

 

[Heiheit]

In the past I have taped a blade with "Please do not sharpen" written on the tape. That did the trick, just for future reference!

 

[Luis G.]

In the past I have taped a blade with "Please do not sharpen" written on the tape. That did the trick, just for future reference!

Aha, thanks for the tip!

Ill check the angle they set it, seems it is not too far form 20 degrees so it may not be too difficult to set.