Question for Umnum, 25 and Inkosi owners.

M

Mick_1KRR

Joined
May 1, 2016
Messages
1,218
Hoping to get some long term owners replying to this. After long term use, has the ceramic ball wear on the tang of your blade caused a noticeable divot or cut into the steel from the ceramic, or is it more of a polish wear mark. Can you noticeably feel it with your finger nail or a pin head? I'm a Sebenza 21 owner and thinking of pulling the trigger on an Umnum and Inkosi, just always been a question i've wondered about with the new interface. I'd imagine since the ball would be extremely smooth and not finished the same way a ceramic sharpening stone would be, that it would be more of just a polish mark, since it would take a thousand years to re-profile or remove enough steel from a blade with a ceramic of that grit. Cheers
 
I don't have my 2013 25 with me, it's getting a new lanyard. I checked a 25 from 2014, a Umnumzaan from 2013 and an Inkosi from 2017. All of them felt the same, I used a wooden tooth pick and ran it across the lock up mark. It's a polished wear mark. I've used the Umnumzaan and 25 a lot, not much use on the Inkosi. If there is any gouging from the ceramic ball, it's not noticeable.

Don't forget, the Umnumzaan came out first with the detent/lock up ceramic ball.
I've got a Umnumzaan from 2011, but it hasn't been used much.
 
A polished mark is on my 25. If there is any wear it is not noticeable. This is after 3 years of heavy use.
 
Mick_1KRR said:
Hoping to get some long term owners replying to this. After long term use, has the ceramic ball wear on the tang of your blade caused a noticeable divot or cut into the steel from the ceramic, or is it more of a polish wear mark. Can you noticeably feel it with your finger nail or a pin head? I'm a Sebenza 21 owner and thinking of pulling the trigger on an Umnum and Inkosi, just always been a question i've wondered about with the new interface. I'd imagine since the ball would be extremely smooth and not finished the same way a ceramic sharpening stone would be, that it would be more of just a polish mark, since it would take a thousand years to re-profile or remove enough steel from a blade with a ceramic of that grit. Cheers
Click to expand...

Think of it like this. On a normal lock the tang wears away the lock bar. On the 25 the Umnum and the Inkosi the lockbar wears the tang. It is just the opposite side of the lock wearing.

Nothing to worry about.
 
Lapedog said:
Think of it like this. On a normal lock the tang wears away the lock bar. On the 25 the Umnum and the Inkosi the lockbar wears the tang. It is just the opposite side of the lock wearing.

Nothing to worry about.
Click to expand...

Yep, I've always fully understood the concept as i'm a very OCD structural design critic in my own bubble, I was just looking for real world results of the concept, seeing as the true outcome will only be proven with years of use on the clock. Good to hear the polish wear marks are not significant at all. Cheers all
 
Mick_1KRR said:
Yep, I've always fully understood the concept as i'm a very OCD structural design critic in my own bubble, I was just looking for real world results of the concept, seeing as the true outcome will only be proven with years of use on the clock. Good to hear the polish wear marks are not significant at all. Cheers all
Click to expand...

The first versions of the Inkosi actually had a groove cut into the tang of the blade for the ceramic ball to wear into. Later versions removed it as it wasn’t necessary.

28497371110_fc3c405d4d_b.jpg
 
Lapedog said:
The first versions of the Inkosi actually had a groove cut into the tang of the blade for the ceramic ball to wear into. Later versions removed it as it wasn’t necessary.

28497371110_fc3c405d4d_b.jpg
Click to expand...
Yeah i remember these early ones, personally i think it was a great idea structurally, convex surface mating into a concave one is always very secure. Not an issue tho, seems like they are all doing fine without it still. Cheers
 
I have one ‘Zaan with just a polish along the track.
6E1BC011-1A78-4A16-99F5-D6266310372F.jpeg
I have another with a bit of peening...the interesting thing is the peening is just *above* where the wear track is.

E47020DB-70DF-42D6-88C1-283A619E1B1C.jpeg

Several months ago my google-fu found pictures similar to both. In all honesty, the peening concerned me a bit at first. Then I decided not to worry about it. It’s now by far my most carried & most flipped CRK. Hasn’t seemed to cause a problem. If it’s worsening, it’s moving at a glacial pace and I’ll just have my blade replaced in 20 years. ;)

8601BBAD-988D-4876-B624-3D0399F43CE2.jpeg
 
That mark is common. I have a 25 That I bought new when they came out and have used it heavily for several years. It’s as smooth now as the day I got it. Still have yet to take it apart as there has been no need too. There also is zero play in any direction. It’s built like a tank.
 
I've had my tanto Umnumzaan since they first came out in 2009? And it has seen a lot of use and there is just a small polished line where the ceramic ball meets the blade
 
I have noticed on my co-workers Umnum the lock bar has a lot of movement from edge to spine direction in a medium to hard grip. Made in Nov 17. If the Inkosi is the same that will keep me from picking one up. I like no movement in that direction.

But it seems only natural for this ceramic ball lock with out the original groove design.

At least I have my Ti-lock. :)
 
BellaBlades said:
I have noticed on my co-workers Umnum the lock bar has a lot of movement from edge to spine direction in a medium to hard grip. Made in Nov 17. If the Inkosi is the same that will keep me from picking one up. I like no movement in that direction.

But it seems only natural for this ceramic ball lock with out the original groove design.

At least I have my Ti-lock. :)
Click to expand...

That is out of spec and should be returned to CRK for repair. My Inkosi has no lockbar movement from spine to edge side of the handle when open.

Isn’t the lockbar stabilizer on the Zaan supposed to prevent exactly this type of lock movement?
 
BellaBlades said:
I have noticed on my co-workers Umnum the lock bar has a lot of movement from edge to spine direction in a medium to hard grip. Made in Nov 17. If the Inkosi is the same that will keep me from picking one up. I like no movement in that direction.

But it seems only natural for this ceramic ball lock with out the original groove design.

At least I have my Ti-lock. :)
Click to expand...
I ended up getting an inkosi and have been using it a lot, mine doesn't have any movement in that direction. I think maybe as Lapedog said it might be out of spec a bit. A little movement is always going to be normal under a very hard grip with this interface but not a lot and not easily. Just a byproduct of the springy titanium lock bar and the smooth ceramic surface.
 
Lapedog said:
That is out of spec and should be returned to CRK for repair. My Inkosi has no lockbar movement from spine to edge side of the handle when open.



Isn’t the lockbar stabilizer on the Zaan supposed to prevent exactly this type of lock movement?
Click to expand...

His is brand new unused and it has about 1.5mm of of play in that direction. If you squeeze it and let go you can watch the lock bar move back and forth however you do not feel it, only see it. I know one other person with an Umnum and will check it out.

I understand that there is less contact area with the lock and that is part of the reason. I
was thinking next year I can partner up an Inkosi Insingo or Umnum with my Dozier if finances allow it.

My wife and I already have a weekend booked for the Eccks and I will try to check out an Inkosi then.
 
Last edited:
BellaBlades said:
His is brand new unused and it has about 1.5mm of of play in that direction. If you squeeze it and let go you can watch the lock bar move back and forth however you do not feel it, only see it. I know one other person with an Umnum and will check it out.

I understand that there is less contact area with the lock and that is part of the reason. I
was thinking next year I can partner up an Inkosi Insingo or Umnum with my Dozier if finances allow it.
Click to expand...

Regardless of it being brand new and unused that is still not supposed to happen with the lockbar. Also the lockbar stabilizer is supposed to prevent exactly that type of movement in the lockbar as well as stop overextension during unlocking.

Send it to CRK it is a defect, they should repair it for free.
 
Well . It happens to be my supervisor's knife and he doesn't notice it. So I certainly won't point it out.

I will inspect it Thursday and I am pretty sure the lock bar stabilizer is not in spec to prevent that movement. It mostly helps over extension . But I will certainly look into it. Crk/ Dozier are my favorite makers.

This is the same reason Bob only seems to collect Crk's!
 
4mer_FMF said:
I have one ‘Zaan with just a polish along the track.
View attachment 857956
I have another with a bit of peening...the interesting thing is the peening is just *above* where the wear track is.

View attachment 857955

Several months ago my google-fu found pictures similar to both. In all honesty, the peening concerned me a bit at first. Then I decided not to worry about it. It’s now by far my most carried & most flipped CRK. Hasn’t seemed to cause a problem. If it’s worsening, it’s moving at a glacial pace and I’ll just have my blade replaced in 20 years. ;)

View attachment 857957
Click to expand...


This post shows the movement I speak of.
 
The natural movement of the ceramic ball should poish the tang no doubt, but there should be zero peening. Peening should really only be present if there are have been hard negative impacts to the spine of the blade (or extreme flicking open) causing the ceramic ball to impact the steel tang, since the ball is harder it could leave small indents in the steel. But i doubt you've been spine-whacking your umnum? The polish marks can look like they have depth or peening to them because of light reflections, run a pin head across the polish marks, you shouldn't feel any bumps really.

Think of it like sharpening with ceramic or diamond stones, it literally takes forever to remove steel with a fine grit stone, and that's with pressure and intentional back and forth strokes under pressure. Imagine trying to re-profile or remove steel with a ceramic ball that has literally no grit, if measurable it would be in the thousands, as the ball on the CRK knives looks smooth as glass. Thinking of it that way put my mind at ease as to how long it would take for any significant wear on the tang or lock travel. To wear away the angle of steel the blade tang is set to at the engagement point would take an insane amount of time and pressure. I've recently become a real fan of the lockup on the inkosi and umnum, I've had some 21's with some very bad lock stick, nice to not have that worry anymore.
 
You must log in or register to reply here.
Back
Top